快速排序2

/* * Copyright 2014 YU Heng-yang. All rights reserved. *  * quick_sort2.c - Quick sort implementation 2. * * 2014-7-8 YU Heng-yang.  */#include <stdio.h>#include <stdlib.h>#include <assert.h>#include "common.h"void quick_sort(int *arr, int n);int main(int argc, char *argv[]){int *array, n;n = input(&array);quick_sort(array, n);output(array, n);return 0;}void quick_sort(int *arr, int n){int i, j;if (n < 2)return;assert(arr);i = 0;j = n;do {/* choose arr[0] as the pivot is not very good */do ++i; while (i < j && arr[i] < arr[0]);do --j; while (arr[j] > arr[0]);if (i < j)swap(arr, i, j);} while (i < j);swap(arr, 0, j);quick_sort(arr, j);quick_sort(arr + j + 1, n - j - 1);}