Created
October 2, 2019 18:26
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Meetup maze
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const Maze = ` ############################ | |
# # # # # | |
# #### # #### # # #### # | |
# # # # # | |
####### ########## ########## | |
# # # # # # # # | |
# # # # #### # # #### # | |
# # # # | |
# # # #### #### #### #### | |
# # # # # # # # | |
# #### # #### # # #### # | |
# # # # # # # # | |
#### # ####### ####### # # | |
# # # # # # | |
# ####### ####### # # # # | |
# # # # # | |
# #### #### #### #### #### | |
# # # # # # #`; | |
const startPoint = {x: 7, y: 6}; | |
const mazeArray = Maze.split("\n").map(row => row.split('')); | |
enum Move { | |
U = 'Up', | |
D = 'Down', | |
L = 'Left', | |
R = 'Right', | |
} | |
const step = (x: number, y: number, move: Move) => move === Move.U | |
? {x, y: y-1} | |
: (move === Move.D | |
? {x, y: y+1} | |
: (move === Move.L | |
? {x: x-1, y} | |
: {x: x+1, y} | |
) | |
) | |
type Path = Move[] | |
const wall = ({x, y}: {x: number, y: number}) => mazeArray[y][x] === '#'; | |
interface Cell { | |
x: number, | |
y: number, | |
length: number, | |
path: Path, | |
} | |
const isExit = (cell: Cell) => cell.x === 0 || cell.y === 0 || cell.x === mazeArray[0].length - 1 || cell.y === mazeArray.length - 1; | |
const key = ({x, y}: {x: number, y: number}) => `${x},${y}`; | |
const startPointKey = key(startPoint); | |
let lastCells: {[key: string]: Cell} = { | |
[startPointKey]: {...startPoint, length: 0, path: []} | |
} | |
let hash: {[key: string]: Cell} = {...lastCells}; | |
let moves = 0; | |
let found = isExit(lastCells[startPointKey]); | |
let exit: Cell = undefined; | |
while (!found) { | |
let newLast = {}; | |
Object.keys(lastCells).map(cellKey => { | |
const lastCell = lastCells[cellKey]; | |
[Move.U, Move.D, Move.L, Move.R].map(move => { | |
const newCoords = step(lastCell.x, lastCell.y, move); | |
const keyNewCoords = key(newCoords); | |
if (!wall(newCoords) && !hash.hasOwnProperty(keyNewCoords)) { | |
const newCell = {...newCoords, length: lastCell.length + 1, path: [...lastCell.path, move]}; | |
newLast[keyNewCoords] = newCell; | |
hash[keyNewCoords] = newCell; | |
} | |
}) | |
}); | |
console.log(JSON.stringify(newLast)) | |
if (Object.keys(newLast).length === 0) { | |
break; | |
} | |
const check = Object.keys(newLast).reduce((result, cellKey) => result.found ? result : {found: isExit(newLast[cellKey]), cell: newLast[cellKey]}, {found: false, cell: undefined}); | |
found = check.found; | |
if (found) exit = check.cell; | |
lastCells = newLast; | |
} | |
if (exit === undefined) { | |
console.log('Path not found'); | |
} else { | |
console.log(exit.path); | |
} |
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