二分查找

二分查找

#include <stdio.h>
int binary_search(int *a,int p,int q,int ele)
{
    int mid=0;
    if(p>q)
    {
        return 0;
    }
    mid=p+(q-p)/2;
    if(ele==a[mid])
    {
        return mid;
    }
    if(ele<a[mid])
    {
        return binary_search(a,p,mid-1,ele);
    }
    else
    {
        return binary_search(a,mid+1,q,ele);
    }
}
int main()
{
    int a[10]={10,14,19,26,27,31,33,35,42,44};
    printf("%d\n",binary_search(a,0,9,31));
    return 0;
}