#include<stdio.h>
int a[15]
void main()
{
    void sort(int a[]);
    int i;
    ptintf("input 15 numbers:\n");
    for(i=0;i<15;i++)
        scanf("%d",&a[i]);
    printf("\n");
    sort(a);
    void search(int a[],int j);
    int j;
    printf("please enter a number:\n");
    scanf("%d",&j);
    search(j);
}
void sort(int a[])
{
    int x,y,t;
    for(x=0;x<14;x++)
    for(y=0;y<14-x;y++)
        if(a[y]<a[y+1])
        {t=a[y];a[y]=a[y+1];a[y+1]=t;}
}
void search(int a[],int j)
{
    int i,x,left=0,right=14,mid,find=0;
        do{
            mid=(left+right)/2;
            if (x=a[mid])
            {printf("a[%d]\n",mid);find=1;}
            else if(x>a[mid])  
            {right=mid;}
                else if(x<a[mid])  
                {left=mid+1;}
                while(left<=right&&find==0);
                if(find==0)
                {printf("无此数");}
                else {printf("\n");}
        }
}