本文实例为大家分享C++二分查找算法，通过改变边界位置来进行查找的方法，代码如下：
#include <iostream>
using namespace std;
int search(int *p,int length,int key);
int search1(int *p,int key);
int main()
{
cout << "Hello world!" << endl;
int a[] = {1,2,3,4,5,6,7,8,9,10,11,12,13,14};
int len = sizeof(a)/sizeof(int);
int pos = search1(a,len,8);
cout << pos << endl;
return 0;
}
int search1(int *p,int key)
{
int left=0;
int right=length-1;
while(left<=right)
{
int mid = (left+right)/2;
if(p[mid]>=key)
{
right = mid-1;
}else
{
left = mid+1;
}
}
if(left<length && p[left]==key)
return left;
return -1;
}
int search(int *p,int key)
{
int left=0;
int right = length -1;
while(left<=right)
{
int mid = (left+right)/2;
if(p[mid]==key)
{
return mid;
}
if(p[mid] > key)
{
right = mid+1;
}
if(p[mid]<key)
{
left=mid-1;
}
}
return -1;
}
