/* 

2016-11-17 11:30:14 

快速排序 

 */ 

 #include<stdio.h> 

 #include <stdlib.h> 



 void QuickSort(int a[], int low, int high); 

 int FindPos(int* a, int low, int high); 



 int main(void) 

 { 

int a[10] = { 11, -8, 4, 54, 1, -99, 42, 23, 45, 68 }; 

 

QuickSort(a, 0, 9);    //第二个参数是第一个元素的下标，第三个参数是最后一个元素的坐标 

 

for (int i = 0; i < 10; i++) 

{ 

printf("%d ", a[i]); 

} 

printf("\n"); 

system("pause"); 

return 0; 

 } 



 void QuickSort(int a[], int low, int high) 

 { 

int pos; 

if (low < high) 

{ 

pos = FindPos(a, low, high); 

QuickSort(a, low, pos - 1); 

QuickSort(a, pos + 1, high); 

} 

 } 



 int FindPos(int* a, int low, int high) 

 { 

int val = a[low]; 
while (low < high)
 
{ 

while (low < high && a[high] >= val) 

--high; 

a[low] = a[high]; 



while (low < high && a[low] <= val) 

++low; 

a[high] = a[low]; 

}    //终止while循环之后low和high一定是相等的 

a[low] = val; 

return low;    //low可以改为high，但不能改为a[low]和a[high] 

 }