验证折半查找算法

#include <stdio.h>
#define MAXL 100
typedef int KeyType;
typedef char InfoType[10];
typedef struct
{
&nbsp; &nbsp; KeyType key; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//KeyType为关键字的数据类型
&nbsp; &nbsp; InfoType data; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//其他数据
} NodeType;
typedef NodeType SeqList[MAXL]; &nbsp; &nbsp; //顺序表类型




int BinSearch(SeqList R,int n,KeyType k)
{
&nbsp; &nbsp; int low=0,high=n-1,mid;
&nbsp; &nbsp; while (low<=high)
&nbsp; &nbsp; {
&nbsp; &nbsp; &nbsp; &nbsp; mid=(low+high)/2;
&nbsp; &nbsp; &nbsp; &nbsp; if (R[mid].key==k) &nbsp; &nbsp; &nbsp;//查找成功返回
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return mid+1;
&nbsp; &nbsp; &nbsp; &nbsp; if (R[mid].key>k) &nbsp; &nbsp; &nbsp; //继续在R[low..mid-1]中查找
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; high=mid-1;
&nbsp; &nbsp; &nbsp; &nbsp; else
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; low=mid+1; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//继续在R[mid+1..high]中查找
&nbsp; &nbsp; }
&nbsp; &nbsp; return 0;
}




int main()
{
&nbsp; &nbsp; int i,n=10;
&nbsp; &nbsp; int result;
&nbsp; &nbsp; SeqList R;
&nbsp; &nbsp; KeyType a[]= {12,18,24,35,47,50,62,83,90,115,134},x=100;
&nbsp; &nbsp; for (i=0; i<n; i++)
&nbsp; &nbsp; &nbsp; &nbsp; R[i].key=a[i];
&nbsp; &nbsp; result = BinSearch(R,n,x);
&nbsp; &nbsp; if(result>0)
&nbsp; &nbsp; &nbsp; &nbsp; printf("序列中第 %d 个是 %d\n",result, x);
&nbsp; &nbsp; else
&nbsp; &nbsp; &nbsp; &nbsp; printf("木有找到！\n");
&nbsp; &nbsp; return 0;

}

<p style="margin-top: 0px; margin-bottom: 0px; padding-top: 0px; padding-bottom: 0px; color: rgb(85, 85, 85); font-family: 'microsoft yahei'; font-size: 15px; line-height: 35px;">运行结果：</p><p style="margin-top: 0px; margin-bottom: 0px; padding-top: 0px; padding-bottom: 0px; color: rgb(85, 85, 85); font-family: 'microsoft yahei'; font-size: 15px; line-height: 35px;">x=47时</p><img src="http://img.blog.csdn.net/20151201185436714" alt="" />

x=90时

x=100时