public class Solution {
public void setZeroes(int[][] matrix) {
boolean firstRowZero = false;
boolean firstColumnZero = false;
//set first row and column zero or not
for(int i=0; i<matrix.length; i++){
if(matrix[i][0] == 0){
firstColumnZero = true;
break;
}
}
for(int i=0; i<matrix[0].length; i++){
if(matrix[0][i] == 0){
firstRowZero = true;
break;
}
}
//mark zeros on first row and column
for(int i=1; i<matrix.length; i++){
for(int j=1; j<matrix[0].length; j++){
if(matrix[i][j] == 0){
matrix[i][0] = 0;
matrix[0][j] = 0;
}
}
}
//use mark to set elements
for(int i=1; i<matrix.length; i++){
for(int j=1; j<matrix[0].length; j++){
if(matrix[i][0] == 0 || matrix[0][j] == 0){
matrix[i][j] = 0;
}
}
}
//set first column and row
if(firstColumnZero){
for(int i=0; i<matrix.length; i++)
matrix[i][0] = 0;
}
if(firstRowZero){
for(int i=0; i<matrix[0].length; i++)
matrix[0][i] = 0;
}
}
}