Sort colors(Dutch flag problem)

3번째 방법 : in-place swap

#include <bits/stdc+++.h>

using namespace std;
void sortColors(int nums[]){
     int idx = 0;
     int idx2 = nums.length - 1;
     int i = 0;
     while ( i<= idx2){
         if(nums[i] == 0){
             swap(nums[i],nums[idx0]);
             idx++;
             i++;
         }else if(nums[i] ==2){
             swap(nums[i], nums[idx2]);
             idx2--;
         }else{
             i++;
         }
     }
}