LeetCode 542. 01 Matrix

542. 01 Matrix

Given a matrix consists of 0 and 1, find the distance of the nearest 0 for each cell.

The distance between two adjacent cells is 1.

Example 1: 
Input:

0 0 0
0 1 0
0 0 0

Output:

0 0 0
0 1 0
0 0 0

Example 2: 
Input:

0 0 0
0 1 0
1 1 1

Output:

0 0 0
0 1 0
1 2 1

Note:

1. The number of elements of the given matrix will not exceed 10,000.
2. There are at least one 0 in the given matrix.
3. The cells are adjacent in only four directions: up, down, left and right.

题意：

对于二维数组中的每一个元素，找距离自己最近的0（上、下、左、右四个方向）

代码：

class Solution {
public:
    vector> updateMatrix(vector>& matrix) {
        int m=matrix.size();
        int n=matrix[0].size();
        vector> dp(m,vector(n,INT_MAX-10000));
        int i, j;
        for(i=0;i=0;i--)//从右边和下边两个方向找
            for(j=n-1;j>=0;j--){
                if(!matrix[i][j]){
                    dp[i][j]=0;
                }
                else{
                    if(i