快速排序

int partition(int arr[],int left,int right)

{

int p, q, x, t;

x = arr[left];

p = left-1;

q = right+1;

while(p+1 != q) {

if(arr[p+1] <= x)

p++;

else if(arr[q-1] > x)

q--;

else {

t = arr[p+1];

arr[++p] = arr[q-1];

arr[--q] = t;

}

}

arr[left] = arr[p];

arr[p] = x;

return p;

}

void quicksort(int arr[], int left, int right)

{

int p;

if (left < right) {

p=partition(arr, left, right);

quicksort(arr, left, p-1);

quicksort(arr, p+1, right);

}

}

使用：

int aa[]={3,2,5,31,65,23,98,21,34,56,77,43,24,88};

quicksort(aa, 0, sizeof(aa)/sizeof(aa[0])-1);