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array_primer.answer.md

配列メニュー

標準入力は以下を使用

const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
// const cols = stream.split(' ')
// const lines = stream.split('\n')
// const matrix = stream.split('\n').map(line => line.split(' '))

【次元配列の入出力】i番目の出力 Boss

STEP: 1 要素数の出力

  • Array.prototype.length
const stream = '5 1 3 4 5 12 6 8 1 3'
const cols = stream.split(' ')

console.log(cols.length)

STEP: 2 全要素の出力

  • Array.prototype.join(SEP)
const stream = '5 1 3 4 5 12 6 8 1 3'
const cols = stream.split(' ')

console.log(cols.join('\n'))

STEP: 3 i 番目の出力

  • Array.prototype.at(INDEX)
  • Array[INDEX]
const stream = '5 1 3 4 5 12 6 8 1 3'
const cols = stream.split(' ')

console.log(cols[4 - 1]) // cols.at(4 - 1)

STEP: 4 配列の入力 1

  • Array.prototype.join(SEP)
const stream = '8 1 3 3 8 1 1 3 8 8'
const cols = stream.split(' ')

console.log(cols.join('\n'))

STEP: 5 配列の入力 2

  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const cols = stream.split(' ')

console.log(cols.join('\n'))

STEP: 6 配列の入力 3

  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [N, A] = stream.split('\n')
const AS = A.split(' ')

console.log(AS.join('\n'))

STEP: 7 i番目の出力 1

  • Array.prototype.at(INDEX)
  • Array[INDEX]
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const K = parseInt(stream)
const cols = '1 3 5 4 6 2 1 7 1 5'.split(' ')

console.log(cols[K - 1]) //cols.at(K - 1)

STEP: 8 i番目の出力 2

  • Array.prototype.at(INDEX)
  • Array[INDEX]
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [K, A] = stream.split('\n')
const AS = A.split(' ')

console.log(AS[parseInt(K) - 1]) // AS.at(parseInt(K) - 1)

final 次元配列の入出力】i番目の出力 Boss

  • Array.prototype.map(FUN)
  • Array.prototype.at(INDEX)
  • Array[INDEX]
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [NK, A] = stream.split('\n')
const [N, K] = NK.map(v => v.split(' ').map(Number))

const AS = A.map(v => v.split(' ').map(Number))
console.log(AS[K - 1]) // AS.at(parseInt(K) - 1)

Matrixにして処理

const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, K], AS] = stream.split('\n').map(line => line.split(' ').map(Number))

console.log(AS[K - 1])

【二次元配列の入出力】i番目の出力 Boss

STEP: 1 要素数の出力

  • Array.length
  • Array.prototype.map(FUN)
  • Array.prototype.flat()
const stream = '1 2 3 4 5 6\n8 1 3 3 1 8'
const lines = stream.split('\n')
const matrix = lines.map(line => line.split(' '))

const result = matrix.flat()
console.log(result.length)

STEP: 2 全要素の出力

  • Array.prototype.map(FUN)
  • Array.prototype.join(SEP)
const stream = '6 5 4 3 2 1\n3 1 8 8 1 3'
const lines = stream.split('\n')
const matrix = lines.map(line => line.split(' '))

const result = matrix.map(v => v.join(' ')).join('\n')
console.log(result)

STEP: 3 行数の出力

  • Array.prototype.map(FUN)
  • Array.length
const stream = '1 2 3\n4 5 6\n8 1 3'
const lines = stream.split('\n')
const matrix = lines.map(line => line.split(' '))

console.log(matrix.length)

STEP: 4 列数の出力

  • Array.prototype.map(FUN)
  • Array.prototype.at(INDEX)
  • Array[INDEX]
  • Array.length
const stream = '1 2 3 4\n6 5 4 3\n3 1 8 1'
const lines = stream.split('\n')
const matrix = lines.map(line => line.split(' '))

const result = matrix[0].length // matrix.at(0).length
console.log(result)

STEP: 5 各行の要素数の出力

  • Array.prototype.map(FUN)
  • Array.length
  • Array.prototype.join(SEP)
const stream = '1\n2 3\n4 5 6'
const lines = stream.split('\n')
const matrix = lines.map(line => line.split(' '))

const result = matrix.map(cols => cols.length)
console.log(result.join('\n'))

STEP: 6 i 行目 j 列目の出力

  • Array.prototype.map(FUN)
  • Array.prototype.at(INDEX)
  • Array[INDEX]
const stream = '1 2 3\n8 1 3\n10 100 1'
const lines = stream.split('\n')
const matrix = lines.map(line => line.split(' '))

const result = matrix[2 - 1][3 - 1] // matrix.at(2 - 1).at(3 - 1)
console.log(result)

STEP: 7 二次元配列の入力 1

  • Array.prototype.map(FUN)
  • Array.prototype.join(SEP)
const stream = '1 3 5 7\n8 1 3 8'
const matrix = stream.split('\n').map(line => line.split(' '))

const result = matrix.map(cols => cols.join(' ')).join('\n')
console.log(result)

STEP: 8 二次元配列の入力 2

  • Array.prototype.map(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[M], ...matrix] = stream.split('\n').map(line => line.split(' '))

const result = matrix.map(cols => cols.join(' ')).join('\n')
console.log(result)

STEP: 9 二次元配列の入力 3

  • Array.prototype.map(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], ...matrix] = stream.split('\n').map(line => line.split(' '))

const result = matrix.map(cols => cols.join(' ')).join('\n')
console.log(result)

STEP: 10 二次元配列の入力 4

  • Array.prototype.map(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], ...matrix] = stream.split('\n').map(line => line.split(' '))

const result = matrix.map(cols => cols.join(' ')).join('\n')
console.log(result)

STEP: 11 i番目の出力 1

  • Array.prototype.map(FUN)
  • Array.prototype.at(INDEX)
  • Array[ROW_INDEX][COL_INDEX]
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [K, L] = stream.split(' ').map(Number)
const a = '1 2 3 4\n10 100 0 5\n8 1 3 8\n15 34 94 25'
const matrix = a.split('\n').map(line => line.split(' '))

const result = matrix[K - 1][L -1] // matrix.at(K - 1).at(L - 1)
console.log(result)

STEP: 12 i番目の出力 2

  • Array.prototype.map(FUN)
  • Array.prototype.at(INDEX)
  • Array[ROW_INDEX][COL_INDEX]
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[K, L], ...matrix] = stream.split('\n').map(line => line.split(' ').map(Number))

const result = matrix[K - 1][L - 1] // matrix.at(K - 1).at(L - 1)
console.log(result)

final 二次元配列の入出力】i番目の出力 Boss

  • Array.prototype.map(FUN)
  • Array.prototype.at(INDEX)
  • Array[ROW_INDEX][COL_INDEX]
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M, K, L], ...matrix] = stream.split('\n').map(line => line.split(' ').map(Number))

const result = matrix[K - 1][L - 1] // matrix.at(K - 1).at(L - 1)
console.log(result)

【配列の検索】何個ある? Boss

STEP: 1 配列に含まれている? 1

  • Array.prototype.includes(TARGET)
const stream = '10 13 21 1 6 51 10 8 15 6'
const cols = stream.split(' ')

const result = cols.includes('6')
console.log(result ? 'Yes' : 'No')

STEP: 2 配列に含まれている? 2

  • Array.prototype.map(FUN)
  • Array.prototype.includes(TARGET)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const N = parseInt(stream)
const cols = '5 12 6 84 14 25 44 3 7 20'.split(' ').map(Number)

const result = cols.includes(N)
console.log(result ? 'Yes' : 'No')

STEP: 3 配列に含まれている? 3

  • Array.prototype.map(FUN)
  • Array.prototype.includes(TARGET)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], AS] = stream.split('\n').map(line => line.split(' ').map(Number))
const result = AS.includes(M)
console.log(result ? 'Yes' : 'No')

STEP: 4 何番目にある? 1

  • Array.prototype.indexOf(TARGET)
const stream = '1 10 2 9 3 8 4 7 5 6'
const cols = stream.split(' ')

const result = cols.indexOf('8') + 1
console.log(result)

STEP: 5 何番目にある? 2

  • Array.prototype.map(FUN)
  • Array.prototype.indexOf(TARGET)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const N = parseInt(stream)
const cols = '1 5 9 7 3 2 4 8 6 10'.split(' ').map(Number)

const result = cols.indexOf(N) + 1
console.log(result)

STEP: 6 何番目にある? 3

  • Array.prototype.map(FUN)
  • Array.prototype.indexOf(TARGET)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], AS] = stream.split('\n').map(line => line.split(' ').map(Number))
const result = AS.indexOf(N) + 1
console.log(result)

STEP: 7 何個ある? 1

  • Array.prototype.filter(FUN)
  • Array.length
const stream = '1 2 2 1 2 1 2 1 1 1'
const cols = stream.split(' ')

const result = cols.filter(v => v === '1').length
console.log(result)
//  別解
//  const result = stream.split('1').length - 1
//  const result = stream.match(/1/g).length

STEP: 8 何個ある? 2

  • Array.prototype.filter(FUN)
  • Array.length
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const N = parseInt(stream)
const cols = '1 2 5 1 4 3 2 5 1 4'.split(' ').map(Number)

const result = cols.filter(v => v === N).length
console.log(result)

final【配列の検索】何個ある? Boss

  • Array.prototype.map(FUN)
  • Array.prototype.filter(FUN)
  • Array.length
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], A] = stream.split('\n').map(line => line.split(' ').map(Number))

const result = A.filter(v => v === N).length
console.log(result)

【文字列の配列】辞書順に出力 Boss

STEP: 1 配列の書き換え

  • Array.prototype.map(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[A, B, N], AS] = stream.split('\n').map(line => line.split(' '))

const result = AS.map(v => v === A ? B : v)
console.log(result.join('\n'))

STEP: 2 2 変数の入れ替え

  • Array.prototype.reverse()
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [A, B] = stream.split(' ')

const result = [A, B].reverse()
console.log(result.join(' '))

STEP: 3 配列の要素の入れ替え

  • Array.prototype.map(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[A, B, N], AS] = stream.split('\n').map(line => line.split(' ').map(Number))
{
  [AS[A - 1], AS[B - 1]] = [AS[B - 1], AS[A - 1]] // swap
}
console.log(AS.join('\n'))

STEP: 4 部分配列

  • Array.prototype.map(FUN)
  • Array.prototype.slice(BIGIN, END)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[A, B, N], AS] = stream.split('\n').map(line => line.split(' ').map(Number))

const result = AS.slice(A - 1, B)
console.log(result.join('\n'))

STEP: 5 配列の連結

  • Array.prototype.map(FUN)
  • Array.prototype.concat()
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], AS, BS] = stream.split('\n').map(line => line.split(' ').map(Number))

const result = [...AS, ...BS] // AS.concat(BS)
console.log(result.join('\n'))

STEP: 6 配列のソート

  • Array.prototype.map(FUN)
  • Array.prototype.sort(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], AS] = stream.split('\n').map(line => line.split(' ').map(Number))

const result = [...AS].sort((a, b) => a - b)
console.log(result.join('\n'))

STEP: 7 配列の反転

  • Array.prototype.map(FUN)
  • Array.prototype.reverse()
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], AS] = stream.split('\n').map(line => line.split(' ').map(Number))

const result = [...AS].reverse()
console.log(result.join('\n'))

STEP: 8 要素のカウント

  • Array.prototype.map(FUN)
  • Array.prototype.filter(FUN)
  • Array.prototype.join(SEP)
  • Array.length
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], AS] = stream.split('\n').map(line => line.split(' ').map(Number))

const result = AS.filter(v => v === M).length
console.log(result)

STEP: 9 配列末尾への追加

  • Array.prototype.map(FUN)
  • Array.prototype.push(VALUE)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], AS] = stream.split('\n').map(line => line.split(' ').map(Number))

const result = [...AS, M]
console.log(result.join('\n'))

破壊的メソッド(push)を使用

const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], AS] = stream.split('\n').map(line => line.split(' ').map(Number))

AS.push(M)
console.log(AS.join('\n'))

STEP: 10 要素の削除

  • Array.prototype.map(FUN)
  • Array.prototype.slice(BIGIN, END)
  • Array.prototype.flat(LEVEL)
  • Array.prototype.splice(START, DELETE_COUNT, ...[ITEM,])
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], AS] = stream.split('\n').map(line => line.split(' ').map(Number))

const result  = [AS.slice(0, M - 1), AS.slice(M)].flat()
console.log(result.join('\n'))

破壊的メソッド(splice)を使用

const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], AS] = stream.split('\n').map(line => line.split(' ').map(Number))

AS.splice(M - 1, 1)
console.log(AS.join('\n'))

STEP: 11 要素の挿入

  • Array.prototype.map(FUN)
  • Array.prototype.slice(BIGIN, END)
  • Array.prototype.flat(LEVEL)
  • Array.prototype.splice(START, DELETE_COUNT, ...[ITEM,])
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M, K], AS] = stream.split('\n').map(line => line.split(' ').map(Number))

const result = [AS.slice(0, M - 1), K, AS.slice(M - 1)].flat()
console.log(result.join('\n'))

破壊的メソッド(splice)を使用

const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M, K], AS] = stream.split('\n').map(line => line.split(' ').map(Number))
AS.splice(M - 1, 0, K)
console.log(AS.join('\n'))

STEP: 12 要素数の出力

  • Array.length
const stream = 'Hello\npaiza\n1234\npa13'
const lines = stream.split('\n')

const result = lines.length
console.log(result)

STEP: 13 全要素の出力

  • Array.prototype.join(SEP)
const stream = 'good\nmorning\npaiza\n813\npa13'
const lines = stream.split('\n')

console.log(lines.join('\n'))

STEP: 14 i 番目の出力

  • Array.prototype.at(INDEX)
const stream = 'good\nmorning\npaiza\n813\npa13'
const lines = stream.split('\n')

const result = lines[3 - 1] // lines.at(3 - 1)
console.log(result)

STEP: 15 文字列の配列の入力 1

  • Array.prototype.join(SEP)
const stream = 'eight\none\nthree\npaiza\npa13\n813'
const lines = stream.split('\n')

console.log(lines.join('\n'))

STEP: 16 文字列の配列の入力 2

  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const cols = stream.split(' ')

console.log(cols.join('\n'))

STEP: 17 文字列の配列の入力 3

  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], SS] = stream.split('\n').map(line => line.split(' '))

console.log(SS.join('\n'))

STEP: 18 i 番目の出力 1

  • Array.prototype.at(INDEX)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const N = parseInt(stream)
const words = 'good\nmorning\npaiza\n813\npa13'.split('\n')

const result = words[N - 1] // words.at(N - 1)
console.log(result)

STEP: 19 i 番目の出力 2

  • Array.prototype.at(INDEX)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], SS] = stream.split('\n').map(line => line.split(' '))

const result = SS[parseInt(N) - 1] // SS.at(parseInt(N) - 1)
console.log(result)

STEP: 20 i 番目の出力 3

  • Array.prototype.map(FUN)
  • Array.prototype.at(INDEX)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], SS] = stream.split('\n').map(line => line.split(' '))

const result = SS[parseInt(N) - 1] // SS.at(parseInt(N) - 1)
console.log(result)

STEP: 21 i 番目の出力 4

  • Array.prototype.map(FUN)
  • Array.prototype.at(INDEX)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M, L], SS] = stream.split('\n').map(line => line.split(' '))

const result =  SS[parseInt(N) - 1][parseInt(L) - 1] // SS.at(parseInt(N) - 1).at(parseInt(L) - 1)
console.log(result)
  • Array.prototype.sort(FUN)
  • Array.prototype.join(SEP)

STEP: 22 辞書順に出力 1

  • Array.prototype.sort(FUN)
  • Array.prototype.join(SEP)
const stream = 'zaipa izapa paiza'
const lines = stream.split(' ')

const result = [...lines].sort()
console.log(result.join('\n'))

STEP: 23 辞書順に出力 2

  • Array.prototype.sort(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const cols = stream.split(' ')

const result = [...cols].sort()
console.log(result.join('\n'))

STEP: 24 辞書順に出力 3

  • Array.prototype.map(FUN)
  • Array.prototype.sort(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], SS] = stream.split('\n').map(line => line.split(' '))

const result = [...SS].sort()
console.log(result.join('\n'))

final 文字列の配列】辞書順に出力 Boss

  • Array.prototype.map(FUN)
  • Array.prototype.sort(FUN)
  • Array.prototype.at(INDEX)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, K], SS] = stream.split('\n').map(line => line.split(' '))

const result = [...SS].sort()[parseInt(K) - 1] // [...SS].sort().at(parseInt(K) - 1)
console.log(result)

フィボナッチ数

STEP: 1 重複の削除

  • Array.prototype.map(FUN)
  • Array.prototype.sort(FUN)
  • Array.prototype.join(SEP)
const stream = '1 3 5 1 2 3 6 6 5 1 4'
const cols = stream.split(' ').map(Number)

const hashset = new Set(cols)
const result = [...hashset].sort()
console.log(result.join('\n'))

STEP: 2 配列の最大最小

  • Array.prototype.map(FUN)
  • Math.prototype.max(...[item1, item2])
  • Math.prototype.min(...[item1, item2])
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], AS] = stream.split('\n').map(line => line.split(' ').map(Number))

const result = [Math.max(...AS), Math.min(...AS)]
console.log(result.join(' '))

STEP: 3 ある数以上以下の要素の列挙 1

  • Array.prototype.map(FUN)
  • Array.prototype.filter(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], AS] = stream.split('\n').map(line => line.split(' ').map(Number))

const result = AS.filter(v => v >= 5)
console.log(result.join('\n')))

STEP: 4 ある数以上以下の要素の列挙 2

  • Array.prototype.map(FUN)
  • Array.prototype.filter(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, K], AS] = stream.split('\n').map(line => line.split(' ').map(Number))

const result = AS.filter(v => v >= K)
console.log(result.join('\n')))

STEP: 5 ある数以上以下の要素の列挙 3

  • Array.prototype.map(FUN)
  • Array.length
  • Array.prototype.filter(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], AS] = stream.split('\n').map(line => line.split(' ').map(Number))

const average = AS.reduce((a, b) => a + b) / AS.length
const result = AS.filter(v => v >= average)
console.log(result.join('\n))

STEP: 6 二点間の距離 1

  • Array.prototype.map(FUN)
  • Math.abs(NUMBER)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], ...AS] = stream.split('\n').map(line => line.split(' ').map(Number))

const result = AS.map(([x, y]) => Math.abs(2 - x) + Math.abs(3 - y))
console.log(result.join('\n'))

STEP: 7 二点間の距離 2

  • Array.prototype.map(FUN)
  • Math.abs(NUMBER)
  • Array.prototype.join(SEP)
// const f = (x1, y1) => ([x2, y2]) => Math.abs(x1 - x2) + Math.abs(y1 - y2)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, A, B], ...AS] = stream.split('\n').map(line => line.split(' ').map(Number))

const [[x1, y1], [x2, y2]] = [AS[A -1], AS[B - 1]] 
const result = Math.abs(x1 - x2) + Math.abs(y1 - y2)
console.log(result)

final フィボナッチ数

  • Array.prototype.map(FUN)
  • Array.prototype.reduce(FUN)
  • Array.prototype.slice(BIGIN, END)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const N = parseInt(stream)

const result = [...Array(N - 2)].reduce((acc, _) => {
  const [a, b] = acc.slice(-2)
  return [...acc, a + b]
}, [0, 1])

console.log(result.join('\n'))
Raw
array_primer.template.md

配列メニュー

標準入力は以下を使用

const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
// const cols = stream.split(' ')
// const lines = stream.split('\n')
// const matrix = stream.split('\n').map(line => line.split(' '))

【次元配列の入出力】i番目の出力 Boss

STEP: 1 要素数の出力

  • Array.prototype.length
const stream = '5 1 3 4 5 12 6 8 1 3'
const cols = stream.split(' ')
// write code here

STEP: 2 全要素の出力

  • Array.prototype.join(SEP)
const stream = '5 1 3 4 5 12 6 8 1 3'
const cols = stream.split(' ')
// write code here

STEP: 3 i 番目の出力

  • Array.prototype.at(INDEX)
const stream = '5 1 3 4 5 12 6 8 1 3'
const cols = stream.split(' ')
// write code here

STEP: 4 配列の入力 1

  • Array.prototype.join(SEP)
const stream = '8 1 3 3 8 1 1 3 8 8'
const cols = stream.split(' ')
// write code here

STEP: 5 配列の入力 2

  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const cols = stream.split(' ')
// write code here

STEP: 6 配列の入力 3

  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [N, A] = stream.split('\n')
// write code here

STEP: 7 i番目の出力 1

  • Array.prototype.at(INDEX)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const K = parseInt(stream)
const cols = '1 3 5 4 6 2 1 7 1 5'.split(' ')
// write code here

STEP: 8 i番目の出力 2

  • Array.prototype.at(INDEX)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [K, A] = stream.split('\n')
// write code here

final 次元配列の入出力】i番目の出力 Boss

  • Array.prototype.map(FUN)
  • Array.prototype.at(INDEX)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [NK, A] = stream.split('\n')
// write code here

Matrixにして処理

const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, K], AS] = stream.split('\n').map(line => line.split(' ').map(Number))
// write code here

【二次元配列の入出力】i番目の出力 Boss

STEP: 1 要素数の出力

  • Array.length
  • Array.prototype.map(FUN)
  • Array.prototype.flat()
const stream = '1 2 3 4 5 6\n8 1 3 3 1 8'
const lines = stream.split('\n')
const matrix = lines.map(line => line.split(' '))
// write code here

STEP: 2 全要素の出力

  • Array.prototype.map(FUN)
  • Array.prototype.join(SEP)
const stream = '6 5 4 3 2 1\n3 1 8 8 1 3'
const lines = stream.split('\n')
const matrix = lines.map(line => line.split(' '))
// write code here

STEP: 3 行数の出力

  • Array.prototype.map(FUN)
  • Array.length
const stream = '1 2 3\n4 5 6\n8 1 3'
const lines = stream.split('\n')
// write code here

STEP: 4 列数の出力

  • Array.prototype.map(FUN)
  • Array.prototype.at(INDEX)
  • Array.length
const stream = '1 2 3 4\n6 5 4 3\n3 1 8 1'
const lines = stream.split('\n')
// write code here

STEP: 5 各行の要素数の出力

  • Array.prototype.map(FUN)
  • Array.length
  • Array.prototype.join(SEP)
const stream = '1\n2 3\n4 5 6'
const lines = stream.split('\n')
// write code here

STEP: 6 i 行目 j 列目の出力

  • Array.prototype.map(FUN)
  • Array.prototype.at(INDEX)
const stream = '1 2 3\n8 1 3\n10 100 1'
const lines = stream.split('\n')
// write code here

STEP: 7 二次元配列の入力 1

  • Array.prototype.map(FUN)
  • Array.prototype.join(SEP)
const stream = '1 3 5 7\n8 1 3 8'
// write code here

STEP: 8 二次元配列の入力 2

  • Array.prototype.map(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
// write code here

STEP: 9 二次元配列の入力 3

  • Array.prototype.map(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
// write code here

STEP: 10 二次元配列の入力 4

  • Array.prototype.map(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
// write code here

STEP: 11 i番目の出力 1

  • Array.prototype.map(FUN)
  • Array.prototype.at(INDEX)
  • Array[ROW_INDEX][COL_INDEX]
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [K, L] = stream.split(' ').map(Number)
const a = '1 2 3 4\n10 100 0 5\n8 1 3 8\n15 34 94 25'
// write code here

STEP: 12 i番目の出力 2

  • Array.prototype.map(FUN)
  • Array.prototype.at(INDEX)
  • Array[ROW_INDEX][COL_INDEX]
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
// write code here

final 二次元配列の入出力】i番目の出力 Boss

  • Array.prototype.map(FUN)
  • Array.prototype.at(INDEX)
  • Array[ROW_INDEX][COL_INDEX]
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
// write code here

【配列の検索】何個ある? Boss

STEP: 1 配列に含まれている? 1

  • Array.prototype.includes(TARGET)
const stream = '10 13 21 1 6 51 10 8 15 6'
const cols = stream.split(' ')
// write code here

STEP: 2 配列に含まれている? 2

  • Array.prototype.map(FUN)
  • Array.prototype.includes(TARGET)
const cols = '5 12 6 84 14 25 44 3 7 20'.split(' ').map(Number)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const N = parseInt(stream)
// write code here

STEP: 3 配列に含まれている? 3

  • Array.prototype.map(FUN)
  • Array.prototype.includes(TARGET)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
// write code here

STEP: 4 何番目にある? 1

  • Array.prototype.indexOf(TARGET)
const stream = '1 10 2 9 3 8 4 7 5 6'
const cols = stream.split(' ')
// write code here

STEP: 5 何番目にある? 2

  • Array.prototype.map(FUN)
  • Array.prototype.indexOf(TARGET)
const cols = '1 5 9 7 3 2 4 8 6 10'.split(' ').map(Number)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const N = parseInt(stream)
// write code here

STEP: 6 何番目にある? 3

  • Array.prototype.map(FUN)
  • Array.prototype.indexOf(TARGET)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
// write code here

STEP: 7 何個ある? 1

  • Array.prototype.filter(FUN)
  • Array.length
const stream = '1 2 2 1 2 1 2 1 1 1'
const cols = stream.split(' ')
// write code here

STEP: 8 何個ある? 2

  • Array.prototype.filter(FUN)
  • Array.length
const cols = '1 2 5 1 4 3 2 5 1 4'.split(' ').map(Number)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const N = parseInt(stream)
// write code here

final【配列の検索】何個ある? Boss

  • Array.prototype.map(FUN)
  • Array.prototype.filter(FUN)
  • Array.length
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
// write code here

【文字列の配列】辞書順に出力 Boss

STEP: 1 配列の書き換え

  • Array.prototype.map(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[A, B, N], AS] = stream.split('\n').map(line => line.split(' '))
// write code here

STEP: 2 2 変数の入れ替え

  • Array.prototype.reverse()
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [A, B] = stream.split(' ')
// write code here

STEP: 3 配列の要素の入れ替え

  • Array.prototype.map(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[A, B, N], AS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))
// write code here

STEP: 4 部分配列

  • Array.prototype.map(FUN)
  • Array.prototype.slice(BIGIN, END)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[A, B, N], AS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))
// write code here

STEP: 5 配列の連結

  • Array.prototype.map(FUN)
  • Array.prototype.concat()
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], AS, BS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))
// write code here

STEP: 6 配列のソート

  • Array.prototype.map(FUN)
  • Array.prototype.sort(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], AS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))
// write code here

STEP: 7 配列の反転

  • Array.prototype.map(FUN)
  • Array.prototype.reverse()
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], AS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))
// write code here

STEP: 8 要素のカウント

  • Array.prototype.map(FUN)
  • Array.prototype.filter(FUN)
  • Array.prototype.join(SEP)
  • Array.length
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], AS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))
// write code here

STEP: 9 配列末尾への追加

  • Array.prototype.map(FUN)
  • Array.prototype.push(VALUE)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], AS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))
// write code here

破壊的メソッド(push)を使用

const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], AS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))

AS.push(M)
console.log(AS.join('\n'))

STEP: 10 要素の削除

  • Array.prototype.map(FUN)
  • Array.prototype.slice(BIGIN, END)
  • Array.prototype.flat(LEVEL)
  • Array.prototype.splice(START, DELETE_COUNT, ...[ITEM,])
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], AS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))
// write code here

破壊的メソッド(splice)を使用

const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], AS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))

AS.splice(M - 1, 1)
console.log(AS.join('\n'))

STEP: 11 要素の挿入

  • Array.prototype.map(FUN)
  • Array.prototype.slice(BIGIN, END)
  • Array.prototype.flat(LEVEL)
  • Array.prototype.splice(START, DELETE_COUNT, ...[ITEM,])
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M, K], AS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))
// write code here

破壊的メソッド(splice)を使用

const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M, K], AS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))
AS.splice(M - 1, 0, K)
console.log(AS.join('\n'))

STEP: 12 要素数の出力

  • Array.length
const stream = 'Hello\npaiza\n1234\npa13'
// write code here

STEP: 13 全要素の出力

  • Array.prototype.join(SEP)
const stream = 'good\nmorning\npaiza\n813\npa13'
// write code here

STEP: 14 i 番目の出力

  • Array.prototype.at(INDEX)
const stream = 'good\nmorning\npaiza\n813\npa13'
// write code here

STEP: 15 文字列の配列の入力 1

  • Array.prototype.join(SEP)
const stream = 'eight\none\nthree\npaiza\npa13\n813'
// write code here

STEP: 16 文字列の配列の入力 2

  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
// write code here

STEP: 17 文字列の配列の入力 3

  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], SS] = stream.split('\n').map(line => line.split(' '))
// write code here

STEP: 18 i 番目の出力 1

  • Array.prototype.at(INDEX)
const S = 'good\nmorning\npaiza\n813\npa13'
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const N = parseInt(stream)
// write code here

STEP: 19 i 番目の出力 2

  • Array.prototype.at(INDEX)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], SS] = stream.split('\n').map(line => line.split(' '))
// write code here

STEP: 20 i 番目の出力 3

  • Array.prototype.map(FUN)
  • Array.prototype.at(INDEX)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M], SS] = stream.split('\n').map(line => line.split(' '))
// write code here

STEP: 21 i 番目の出力 4

  • Array.prototype.map(FUN)
  • Array.prototype.at(INDEX)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, M, L], SS] = stream.split('\n').map(line => line.split(' '))
// write code here
  • Array.prototype.sort(FUN)
  • Array.prototype.join(SEP)

STEP: 22 辞書順に出力 1

  • Array.prototype.sort(FUN)
  • Array.prototype.join(SEP)
const stream = 'zaipa izapa paiza'
// write code here

STEP: 23 辞書順に出力 2

  • Array.prototype.sort(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
// write code here

STEP: 24 辞書順に出力 3

  • Array.prototype.map(FUN)
  • Array.prototype.sort(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], SS] = stream.split('\n').map(line => line.split(' '))
// write code here

final 文字列の配列】辞書順に出力 Boss

  • Array.prototype.map(FUN)
  • Array.prototype.sort(FUN)
  • Array.prototype.at(INDEX)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, K], SS] = stream.split('\n').map(line => line.split(' '))
// write code here

フィボナッチ数

STEP: 1 重複の削除

  • Array.prototype.map(FUN)
  • Array.prototype.sort(FUN)
  • Array.prototype.join(SEP)
const stream = '1 3 5 1 2 3 6 6 5 1 4'
const cols = stream.split(' ').map(Number)

const hashset = new Set(cols)
const result = [...hashset].sort()
console.log(result.join('\n'))

STEP: 2 配列の最大最小

  • Array.prototype.map(FUN)
  • Math.prototype.max(...[item1, item2])
  • Math.prototype.min(...[item1, item2])
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], AS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))
// write code here

STEP: 3 ある数以上以下の要素の列挙 1

  • Array.prototype.map(FUN)
  • Array.prototype.filter(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], AS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))
// write code here

STEP: 4 ある数以上以下の要素の列挙 2

  • Array.prototype.map(FUN)
  • Array.prototype.filter(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, K], AS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))
// write code here

STEP: 5 ある数以上以下の要素の列挙 3

  • Array.prototype.map(FUN)
  • Array.length
  • Array.prototype.filter(FUN)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], AS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))
// write code here

STEP: 6 二点間の距離 1

  • Array.prototype.map(FUN)
  • Math.abs(NUMBER)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N], ...AS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))
// write code here

STEP: 7 二点間の距離 2

  • Array.prototype.map(FUN)
  • Math.abs(NUMBER)
  • Array.prototype.join(SEP)
// const f = (x1, y1) => ([x2, y2]) => Math.abs(x1 - x2) + Math.abs(y1 - y2)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const [[N, A, B], ...AS] = stream.split('\n')
  .map(line => line.split(' ').map(Number))
// write code here

final フィボナッチ数

  • Array.prototype.map(FUN)
  • Array.prototype.reduce(FUN)
  • Array.prototype.slice(BIGIN, END)
  • Array.prototype.join(SEP)
const stream = require('fs').readFileSync('/dev/stdin', 'utf8').trim()
const N = parseInt(stream)

const result = [...Array(N - 2)].reduce((acc, _) => {
  const [a, b] = acc.slice(-2)
  return [...acc, a + b]
}, [0, 1])

console.log(result.join('\n'))
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