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| 1 | +package ivanmarkovic.algorithms.recursion; |
| 2 | + |
| 3 | +import java.util.Stack; |
| 4 | + |
| 5 | +public class Maze { |
| 6 | + |
| 7 | + public static void main(String args[]) { |
| 8 | + Stack<int []> stack = new Stack<>(); |
| 9 | + int numbers[] = {0, 0}; |
| 10 | + stack.push(numbers); |
| 11 | + |
| 12 | + int matrix[][] = new int[5][5]; |
| 13 | + for(int i = 0; i < matrix.length; i++) |
| 14 | + for(int j = 0; j < matrix[i].length; j++) |
| 15 | + matrix[i][j] = 0; |
| 16 | + |
| 17 | + |
| 18 | + matrix[0][0] = 1; // Must be 1, it's starting position |
| 19 | + for(int i = 2; i < matrix[0].length; i++) |
| 20 | + matrix[0][i] = 2; |
| 21 | + matrix[1][0] = 2; |
| 22 | + for(int i = 0; i < matrix[2].length; i++) |
| 23 | + if(i != 2) |
| 24 | + matrix[2][i] = 2; |
| 25 | + for(int i = 0; i < matrix[4].length; i++) |
| 26 | + if(i != 4) |
| 27 | + matrix[4][i] = 2; |
| 28 | + |
| 29 | + |
| 30 | + move(matrix, stack); |
| 31 | + } |
| 32 | + |
| 33 | + public static void move(int matrix[][], Stack<int[]> stack) { |
| 34 | + if(stack.isEmpty()) |
| 35 | + System.out.println("Path not found"); |
| 36 | + else { |
| 37 | + int newCoords[] = new int[2]; |
| 38 | + int coords[] = new int[2]; |
| 39 | + coords = stack.peek(); |
| 40 | + Integer x = coords[0]; |
| 41 | + Integer y = coords[1]; |
| 42 | + if(x == matrix.length - 1 && y == matrix[x].length - 1) { |
| 43 | + System.out.println("Path found"); |
| 44 | + } |
| 45 | + else if(y < matrix[x].length - 1 && matrix[x][y + 1] == 0) { // can go right |
| 46 | + matrix[x][y + 1] = 1; |
| 47 | + newCoords[0] = x; |
| 48 | + newCoords[1] = y + 1; |
| 49 | + stack.push(newCoords); |
| 50 | + move(matrix, stack); |
| 51 | + } |
| 52 | + else if(x - 1 >= 0 && matrix[x - 1][y] == 0) { // can go up |
| 53 | + matrix[x - 1][y] = 1; |
| 54 | + newCoords[0] = x - 1; |
| 55 | + newCoords[1] = y; |
| 56 | + stack.push(newCoords); |
| 57 | + move(matrix, stack); |
| 58 | + } |
| 59 | + else if(y - 1 >= 0 && matrix[x][y - 1] == 0) { // can go left |
| 60 | + matrix[x][y - 1] = 1; |
| 61 | + newCoords[0] = x; |
| 62 | + newCoords[1] = y - 1; |
| 63 | + stack.push(newCoords); |
| 64 | + move(matrix, stack); |
| 65 | + } |
| 66 | + else if(x < matrix.length - 1 && matrix[x + 1][y] == 0) { // can go down |
| 67 | + matrix[x + 1][y] = 0; |
| 68 | + newCoords[0] = x + 1; |
| 69 | + newCoords[1] = y; |
| 70 | + stack.push(newCoords); |
| 71 | + move(matrix, stack); |
| 72 | + } |
| 73 | + else { |
| 74 | + stack.pop(); |
| 75 | + move(matrix, stack); |
| 76 | + } |
| 77 | + } |
| 78 | + } |
| 79 | +} |
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