#include<stdio.h>

int main(){

    int a[]={,,,,,,,,,,,,,,};

    int l=sizeof(a)/;        //长度

    int x=;                //要查找到的值 

    int Bisection(int x,int* a,int l);

    Bisection(x,a,l); 

    return ;

} 

int Bisection(int x,int* a,int l){

    int address;    //查找的数的位置

    //先考虑两端的位置

    if(x==a[l-]){

        address=l-;

        printf("%d\n",address);

        return address;

    }else if(x==a[]){

        address=;

        printf("%d\n",address);

        return address;

    }

    //如果不在两端

    address=l/;

    l=l/;

    while(true){

        if(x==a[address]){

            printf("%d\n",address);

            break;

        }else if(x>a[address]){

            l=l/;

            address=address+l;

        }else if(x<a[address]){

            l=l/;

            address=address-l;

        }

        if(l==){

            //如果l=0了表示找不到

            printf("not found");

            break;

        }

    }

    return address;

}