Given a matrix consists of 0 and 1, find the distance of the nearest 0 for each cell.java
The distance between two adjacent cells is 1.
Example 1:rest
Input: 0 0 0 0 1 0 0 0 0 Output: 0 0 0 0 1 0 0 0 0
Example 2:
Input:code
0 0 0 0 1 0 1 1 1 Output: 0 0 0 0 1 0 1 2 1
Note:
The number of elements of the given matrix will not exceed 10,000.
There are at least one 0 in the given matrix.
The cells are adjacent in only four directions: up, down, left and right.element
public class ZeroOneMatrix { public int[][] updateMatrix(int[][] matrix) { int m = matrix.length; int n = matrix[0].length; Queue<int[]> queue = new LinkedList<>(); for (int i = 0; i < m; i++) { for (int j = 0; j < n; j++) { if (matrix[i][j] == 0) { queue.offer(new int[]{i, j}); }else { matrix[i][j] = Integer.MAX_VALUE; } } } int[][] dirs = {{-1, 0}, {1, 0}, {0, -1}, {0, 1}}; while (!queue.isEmpty()) { int[] cell = queue.poll(); for (int[] d : dirs) { int r = cell[0] + d[0]; int c = cell[1] + d[1]; if (r < 0 || r >= m || c < 0 || c >= n || matrix[r][c] <= matrix[cell[0]][cell[1]] + 1) continue; queue.offer(new int[] {r, c}); matrix[r][c] = matrix[cell[0]][cell[1]] + 1; } } return matrix; } }