经典排序之选择排序

#include <stdio.h>
int main()
{
    int i,j,index,k;
    int tem,length;
    int a[10]={2,24,3,19,45,12,1,66,34,7};
//    length = a.length();
    length = 10;
    printf("Before ordered:\n");
    for(i = 0; i < length; i++)
    printf("%d ",*(a+i));
    printf("\n\n");
    for(i = 0; i < length; i++)
    {
        index = i;
       for(j = i+1; j < length; j++)
       {
             if(a[j]>a[index])
            index = j;
       }
        if(index != i)
        {
            tem = a[index];
            a[index] = a[i];
            a[i] = tem;
        }
        printf("The %d time select order:\n",i);
        for(k = 0; k < length; k++)
        printf("%d ",*(a+k));
        printf("\n\n");
    }
    printf("After ordered:\n");
    for(i = 0; i < length; i++)
    printf("%d ",*(a+i));
    printf("\n");
    return 0;
}

选择排序类似于冒泡排序，但是不同之处是，每次找到最大（或最小）的下标然后放在前边，其复杂度o(n)^2