4.26

#include<stdio.h>
#define N 10
main(){
int i,a[N]={-3,4,7,9,13,45,67,89,100,180},low=0,high=N-1,mid,k=-1,m;
printf("a数组中的数据如下:\n");
for(i=0;i<N;i++)
printf("%d",a[i]);
printf("\n");
printf("Enter m:");
scanf("%d",&m);
while(low<=high)
{
mid=(low+high)/2;
if(m<a[mid])
high=mid-1;
else
if(m>a[mid])
low=mid+1;
else
{k=mid;
break;}
}
if(k>=0)
printf("m=%d,index=%d\n",m,k);
else
printf("Not be found!\n");
}