02.c

算法设计与分析实验报告

#include <stdio.h>
main()
{int a[9]={0,15,20,25,27,28,29,31,43};
int low=1,high=9,j=0,mid,x;
 printf("Please input a number:\n");
 scanf("%d",&x);
 while(low<=high&&j==0)
   mid=(low+high)/2;
   if(x=a[mid])
     j=mid;
   if(x<a[mid])
     high=mid-1;
   else
     low=mid+1;
 printf("%d",j);
}