C语言-二分法入门

输入十个数，求中间的….

#include<cstdio>

int binary_search(int arr[],int SizeOfArray,int key);

int binary_search(int arr[],int SizeOfArray,int key){

    int left=0,mid;
    int right=SizeOfArray-1;

    while(left<=right){
        mid=(left+right)/2;
        if(key==arr[mid])
           printf("%d",mid);
           break;
        if(key<arr[mid])
            right=mid-1;
        if(key>arr[mid])
            left=mid+1;
    }

    return -1;
}

int main()
{
    int key;
    scanf("%d",&key);
    int a[10]={1,2,3,4,5,6,7,8,9,10};
    binary_search(a,9,key);

    return 0;
}

测试

/* 1 2 3 4 5 6 7 8 9 */