```
quick_sort(nums, 0, numsSize - 1);
int sum = 0;
int k;
for (k = 0; k < numsSize; k += 2) {
sum += nums[k];
}
return sum;
}
int partition(int* arr, int low, int high){
int key;
key = arr[low];
while(low<high){
while(low <high && arr[high]>= key )
high--;
if(low<high)
arr[low++] = arr[high];
while( low<high && arr[low]<=key )
low++;
if(low<high)
arr[high--] = arr[low];
}
arr[low] = key;
return low;
}
void quick_sort(int* arr, int start, int end){
int pos;
if (start<end){
pos = partition(arr, start, end);
quick_sort(arr,start,pos-1);
quick_sort(arr,pos+1,end);
}
return;
}
```