# Color Sort

22 Nov 2019The idea is simple, you need to put all 0 in the left, and all 2 on right, and leave 1 in the middle;

So we could do this with one 0-pointer, and one 2-pointer, which in general case, can be called: p_min, p_max; Ok, we could start iterate the nums, and what we need to do is keep 0 on left and 2 on right;

```
public void sortColors(int[] nums) {
int p_min = 0;
int p_max = nums.length-1;
int i = 0;
// continue increase i, when we are not out of boundery;
while(i<=p_max) {
if(nums[i] == 0) {
// if we found min, we just swap it with the current index, and keep going
swap(nums, i, p_min);
i++;
p_min++;
} else if (nums[i] == 1) {
// if we found i, just leave it there and continue;
i++;
} else {
// if we found 2, let`s swap it to the end of the array, and update the p_max index smaller( cuz the last position is already the biggest, we need to find next one to swap);
swap(nums, i, p_max);
p_max--;
}
}
}
// normal swap procedure
private void swap(int[] n, int i, int j) {
int temp = n[i];
n[i] = n[j];
n[j] = temp;
}
}
```