求C语言折半查找法 代码

拿15个静态常量做的测试

#include<stdio.h>

//要先写 第一个元素的值为0的排除子函数，没写。

int arrange(int x,int a[],int low,int high)

{

int flag=0;

int mid =(low+high)/2;

if((high-low)==0 || (high - low) == 1) //二分法排序的最后两种可能

{

if(a[mid]==x)

return x;

else

return 0;

}

int left;

int right;

left=arrange(x,a,low,mid); //向左

right=arrange(x,a,mid,high); //向右

if(left||right) //整合，有一个非0就是找到值了

return a[left+right];

else

return 0;

}

int main()

{

int a[]={-8,-5,-2,-1,2,5,8,10,18,21,23,7,9,1,13};

int result,x;

printf(" {12,14,15,16,2,5,8,10,18,21,23,7,9,1,13} \n");

printf("input the number you want:");

scanf("%d",&x);

result=arrange(x,a,1,15);

if( result != 0)

printf("%d\n",result);

else

printf("there is no number!\n");

return 0;

}