c_cpp 【分治法】二分搜索技术【2.3】

Posted 2021-05-14

//2d3 二分搜索技术
#include "stdafx.h"
#include <iostream>
using namespace std;

template<class Type>
int BinarySearch(Type a[],const Type& x,int n);

int main()
{
    int x = 6;
    int a[10];
    for(int i=0; i<10; i++)
    {
        a[i] = i + 1;
    }
    cout<<BinarySearch(a,x,10)<<endl;
    return 0;
}

template<class Type>
int BinarySearch(Type a[],const Type& x,int n)
{
    int left = 0;
    int right = n-1;
    while(left<=right)
    {
        int mid = (left + right)/2;
        if(x == a[mid])
        {
            return mid;
        }
        if(x>a[mid])
        {
            left = mid + 1;
        }
        else
        {
            right = mid - 1;
        }
    }

    return -1;
}