diff --git a/Backtracking/RatInAMaze.js b/Backtracking/RatInAMaze.js new file mode 100644 index 000000000..c1d3297a9 --- /dev/null +++ b/Backtracking/RatInAMaze.js @@ -0,0 +1,55 @@ +/* + * Problem Statement: + * - 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 + * + */ + +const outOfBoundary = (grid, currentRow, currentColumn) => { + if (currentRow < 0 || currentColumn < 0 || currentRow >= grid.length || currentColumn >= grid[0].length) return true + else return false +} + +const isPossible = (grid, currentRow, currentColumn) => { + if (outOfBoundary(grid, currentRow, currentColumn)) return false + + console.log(currentRow, currentColumn) + if (grid[currentRow][currentColumn] === 0) return false + + if (currentRow === targetRow && currentColumn === targetColumn) { + return true + } + + const directions = [ + [1, 0], + [0, 1], + [-1, 0], + [0, -1] + ] + + for (let i = 0; i < directions.length; i++) { + const nextRow = currentRow + directions[i][0]; const nextColumn = currentColumn + directions[i][1] + grid[currentRow][currentColumn] = 0 + if (isPossible(grid, nextRow, nextColumn)) return true + grid[currentRow][currentColumn] = 1 + } + return false +} + +// Driver Code + +const grid = [ + [1, 1, 1, 1], + [1, 0, 0, 1], + [0, 1, 0, 1], + [1, 1, 1, 1] +] + +const targetRow = grid.length - 1 +const targetColumn = grid[0].length - 1 + +if (isPossible(grid, 0, 0)) { + console.log('Possible') +} else { + console.log('Not Possible') +}