algorithm/JavaScript
1
0
Fork 0
mirror of https://github.com/TheAlgorithms/JavaScript.git synced 2025-07-06 09:28:26 +08:00
Code Issues Packages Projects Releases Wiki Activity

RatInAMaze prints path now

Browse Source
This commit is contained in:
Chiranjeev
2021-08-22 23:24:13 +05:30
parent 9b37cb0705
commit 51c5ea48b8
1 changed files with 43 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files

73
Backtracking/RatInAMaze.js
View File

@ -3,52 +3,65 @@
* - Given a NxN grid, find whether rat in cell (0,0) can reach target(N-1,N-1); * - Given a NxN grid, find whether rat in cell (0,0) can reach target(N-1,N-1);
* - In grid "0" represent blocked cell and "1" represent empty cell * - In grid "0" represent blocked cell and "1" represent empty cell
* *
* Reference for this problem:
* - https://www.geeksforgeeks.org/rat-in-a-maze-backtracking-2/
*
*/ */
// Helper function to find if current cell is out of boundary
const outOfBoundary = (grid, currentRow, currentColumn) => { const outOfBoundary = (grid, currentRow, currentColumn) => {
if (currentRow < 0 || currentColumn < 0 || currentRow >= grid.length || currentColumn >= grid[0].length) return true if (currentRow < 0 || currentColumn < 0 || currentRow >= grid.length || currentColumn >= grid[0].length) {
else return false return true
} else {
return false
}
} }
const isPossible = (grid, currentRow, currentColumn) => { const printPath = (grid, currentRow, currentColumn, path) => {
if (outOfBoundary(grid, currentRow, currentColumn)) return false // If cell is out of boundary, we can't proceed
if (outOfBoundary(grid, currentRow, currentColumn)) return false
if (grid[currentRow][currentColumn] === 0) return false // If cell is blocked then you can't go ahead
if (grid[currentRow][currentColumn] === 0) return false
if (currentRow === targetRow && currentColumn === targetColumn) { // If we reached target cell, then print path
return true if (currentRow === targetRow && currentColumn === targetColumn) {
} console.log(path)
return true
}
const directions = [ // R,L,D,U are directions `Right, Left, Down, Up`
[1, 0], const directions = [
[0, 1], [1, 0, 'D'],
[-1, 0], [-1, 0, 'U'],
[0, -1] [0, 1, 'R'],
] [0, -1, 'L']
]
for (let i = 0; i < directions.length; i++) { for (let i = 0; i < directions.length; i++) {
const nextRow = currentRow + directions[i][0]; const nextColumn = currentColumn + directions[i][1] const nextRow = currentRow + directions[i][0]
grid[currentRow][currentColumn] = 0 const nextColumn = currentColumn + directions[i][1]
if (isPossible(grid, nextRow, nextColumn)) return true const updatedPath = path + directions[i][2]
grid[currentRow][currentColumn] = 1
} grid[currentRow][currentColumn] = 0
return false if (printPath(grid, nextRow, nextColumn, updatedPath)) return true
grid[currentRow][currentColumn] = 1
}
return false
} }
// Driver Code // Driver Code
const grid = [ const grid = [
[1, 1, 1, 1], [1, 1, 1, 1],
[1, 0, 0, 1], [1, 0, 0, 1],
[0, 0, 1, 0], [0, 0, 1, 1],
[1, 1, 0, 1] [1, 1, 0, 1]
] ]
const targetRow = grid.length - 1 const targetRow = grid.length - 1
const targetColumn = grid[0].length - 1 const targetColumn = grid[0].length - 1
if (isPossible(grid, 0, 0)) { // Variation 2 : print a possible path to reach from (0, 0) to (N-1, N-1)
console.log('Possible') // If there is no path possible then it will print "Not Possible"
} else { !printPath(grid, 0, 0, '') && console.log('Not Possible')
console.log('Not Possible')
}