快速排序，c语言实现(基础版)

qsort.c

# include <stdio.h>

void swap(int v[], int i, int j){
  int temp = v[i];
  v[i] = v[j];
  v[j] = temp;
}

void qsort(int v[], int left, int right){
  int i, last;
  if(left >= right)
    return;
  last = left;
  for(i = left+1; i <= right; i++){
    if(v[i] <= v[left])
      swap(v, ++last, i);
  }
  swap(v, last, left);
  qsort(v, left, last-1);
  qsort(v, last+1, right);
}

int main(){
  int v[] = {4, 2, 3, 1, 8, 6, 3, 7, 5, 10, 21, 19};
  int length = 12;
  qsort(v, 0, length-1);
  for(int i=0; i<length; i++){
    printf("%d%s", v[i], i == length-1 ? "\n": ", ");
  }
}