Set Matrix Zeroes

转自：http://blog.youkuaiyun.com/linhuanmars/article/details/24066199

class Solution {
public:
    void setZeroes(vector<vector<int> > &matrix) {
        if(matrix.empty() || matrix[0].empty()) {
            return;
        }

        int m = matrix.size();
        int n = matrix[0].size();
        bool rowZero = false;
        bool colZero = false;
        for(int i = 0; i < n; i++) {
            if(matrix[0][i] == 0) {
                rowZero = true;
                break;
            }
        }
        for(int i = 0; i < m; i++) {
            if(matrix[i][0] == 0) {
                colZero = true;
                break;
            }
        }

        for(int i = 1; i < m; i++) {
            for(int j = 1; j < n; j++) {
                if(matrix[i][j] == 0) {
                    matrix[0][j] = 0;
                    matrix[i][0] = 0;
                }
            }
        }
        for(int i = 1; i < m; i++) {
            for(int j = 1; j < n; j++) {
                if(matrix[0][j] == 0 || matrix[i][0] == 0) {
                    matrix[i][j] = 0;
                }
            }
        }

        if(rowZero) {
            for(int i = 0; i < n; i++) {
                matrix[0][i] = 0;
            }
        }

        if(colZero) {
            for(int i = 0; i < m; i++) {
                matrix[i][0] = 0;
            }
        }
    }
};