程序代码：

#include<stdio.h>
#include<math.h>
void main()
{
    static int a[15]={2,6,8,9,12,23,34,45,56,67,78,89,90,123,456};
    int i,j,m;
    scanf("%d",&m);
    for(j=0;j<15;j++)
        printf("%4d",a[j]);
    printf("\n");
    i=7;
    while(fabs(i-7)<8)
    {
        if(m<a[7])
        {
            if(a[i]-m==0)
            {
                printf("it is at (%d)\n",i+1);
                break;
            }
            i--;
        }
        else
            if(m>a[7])
            {
                if(a[i]-m==0)
                {
                    printf("it is at (%d) \n",i+1);
                    break;
                }
                i++;
            }
            else
                printf("8\n");
    }
        if(fabs(i-7)-8==0)
            printf("there is not\n");
}

程序代码：

int bisearch(int num[],int dim,int find)//dim表示尺寸
{
    int low,mid,upper;
    int j=0;

    low=0;
    upper=dim-1;

    while(low<=upper)
    {
        mid=(low+upper)/2;
        if(num[mid]<find)
        {
            low=mid+1;
        }
        else if(num[mid]>find)
        {
            upper=mid-1;
        }
        else
        {
            break;
        }
    }
return  -1;
}