5.8

问题描述：

在一维数组中用二分法寻找中间项

问题分析：

将所有数分为两组，不停的进行二分操作，利用mid作为指针在数组中不停细分

代码：#include<stdio.h>

#define N 10

main()

{

       int i ,a[N]={-1,3,7,14,18,31,39,56,65,73},low=0,high=N-1,mid,k=-1,m;

       printf("a数组中的数据为：",\n);

       for(i=1;1<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;

       }

}