Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in place.
Follow up:
Did you use extra space?
A straight forward solution using O(mn) space is probably a bad idea.
A simple improvement uses O(m + n) space, but still not the best solution.
Could you devise a constant space solution?
public class Solution {
public void setZeroes(int[][] matrix) {
if(matrix == null || matrix.length == 0 || matrix[0].length == 0) return;
int row = 0, col = 0;
boolean sig = true;
for(int i = 0; i < matrix.length; i ++){
for(int j = 0; j < matrix[0].length; j ++){
if(matrix[i][j] == 0){
if(sig){
row = i;
col = j;
sig = false;
} else {
matrix[row][j] = 0;
matrix[i][col] = 0;
}
}
}
}
if(sig) return;
for(int i = 0; i < matrix.length; i ++){
for(int j = 0; j < matrix[0].length; j ++){
if((matrix[row][j] == 0 || matrix[i][col] == 0) && i != row && j != col) matrix[i][j] = 0;
}
}
for(int i = 0; i < matrix.length; i ++){
matrix[i][col] = 0;
}
for(int j = 0; j < matrix[0].length; j ++){
matrix[row][j] = 0;
}
}
}