alldroll

// https://leetcode.com/problems/implement-trie-prefix-tree

type Trie struct {
    root *TrieNode
}

type TrieNode struct {
    children []*TrieNode
    isLeaf bool
}

alldroll

// https://leetcode.com/problems/minimum-size-subarray-sum/

func minSubArrayLen(s int, nums []int) int {
    n := len(nums)
    sum, min := 0, n + 1
    
    for i, j := 0, 0; j < n && i < n; j++ {
        sum += nums[j]
        
        for i <= j && sum >= s {

alldroll

// https://leetcode.com/problems/course-schedule-ii

func findOrder(numCourses int, prerequisites [][]int) []int {
    graph := make([][]int, numCourses)
    indirects := make([]int, numCourses)
    
    for _, pair := range prerequisites {
        from, to := pair[0], pair[1]
        graph[from] = append(graph[from], to)
        indirects[to]++

alldroll

/*
https://leetcode.com/problems/add-and-search-word-data-structure-design/

This solution based on the key idea of search engines: Inverted Index
Please have a look at this https://nlp.stanford.edu/IR-book/html/htmledition/an-example-information-retrieval-problem-1.html

Or take a look at this open source project https://github.com/suggest-go/suggest

Briefly description:

alldroll

// https://leetcode.com/problems/house-robber-ii 

func rob(nums []int) int {
    n := len(nums)
    
    if n == 0 {
        return 0
    }
    
    if n == 1 {

alldroll

// https://leetcode.com/problems/kth-largest-element-in-an-array

import "container/heap"

type Heap []int

func (h Heap) Swap(i, j int) {
    h[i], h[j] = h[j], h[i]
}

alldroll

// https://leetcode.com/problems/combination-sum-iii

func combinationSum3(k int, n int) [][]int {
    if k == 1 {
        return [][]int{{n}}
    }
    
    result := [][]int{}
    combination(1, k, n, []int{}, &result)
    

alldroll

// https://leetcode.com/problems/maximal-square

func maximalSquare(matrix [][]byte) int {
    n := len(matrix)
    
    if n == 0 {
        return 0
    }
    
    m := len(matrix[0])

alldroll

// https://leetcode.com/problems/basic-calculator-ii

import "strings"

const (
    space = rune(' ')
    plus = rune('+')
    minus = rune('-')
    divide = rune('/')
    asterisk = rune('*')

alldroll

// https://leetcode.com/problems/summary-ranges

func summaryRanges(nums []int) []string {
    numsLen := len(nums)
    
    if numsLen == 0 {
        return []string{}
    }
    
    ranges := []string{}