快速排序方法之一
先找到第一个元素的位置,将数据分为两部分,然后通过递归调用实现
例子程序
#include <stdio.h>
void QuickSort(int *a, int low, int high);
int FindPos(int *a, int low, int high);
int main(void)
{
int a[6] = {2,1,0,5,4,3};
int i;
QuickSort(a,0,5); //0 第一个元素下标 5最后一个元素下标
for(i=0; i<6;++i)
printf("%d ",a[i]);
printf("\n");
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);
}
return ;
}
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];
}
a[low] = val;
return high;//low == high
}
编译
gcc quicksort.c -o quicksort
结果测试
test# ./quicksort
0 1 2 3 4 5