### Problem

Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in place.

Input ::
[
[1,2,3,4],
[1,2,0,4],
[1,0,3,4],
[1,2,3,4]
]

Output ::
[
[1,2,0,4],
[1,2,0,4],
[0,0,0,0],
[1,2,0,4]
]

### JavaScript Code

```function setZeroes(matrix) {
var firstRowZero = false;
var firstColumnZero = false;

//set first row and column zero or not
for(var i=0; i<matrix.length; i++){
if(matrix[i][0] == 0){
firstColumnZero = true;
break;
}
}

for(var i=0; i<matrix[0].length; i++){
if(matrix[0][i] == 0){
firstRowZero = true;
break;
}
}

//mark zeros on first row and column
for(var i=1; i<matrix.length; i++){
for(var 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(var i=1; i<matrix.length; i++){
for(var 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(var i=0; i<matrix.length; i++)
matrix[i][0] = 0;
}

if(firstRowZero){
for(var i=0; i<matrix[0].length; i++)
matrix[0][i] = 0;
}

return matrix;
}
```