矩阵置零,leetcode
public void setZeroes(int[][] matrix) {
int m = matrix.length, n = matrix[0].length;
boolean flagCol = false;
for (int i = 0; i < m; i++) {
if (!flagCol && matrix[i][0] == 0) {
flagCol = true;
}
for (int j = 1; j < n; j++) {
if (matrix[i][j] == 0) {
matrix[i][0] = matrix[0][j] = 0;
}
}
}
for (int i = m - 1; i >= 0; i--) {
for (int j = 1; j < n; j++) {
if (matrix[i][j] != 0 && (matrix[i][0] == 0 || matrix[0][j] == 0)) {
matrix[i][j] = 0;
}
}
if (matrix[i][0] != 0 && flagCol) {
matrix[i][0] = 0;
}
}
}