分治法之二分查找

#include <iostream>
#include <algorithm>
using namespace std;
const int M = 10000;
int x,n,i;
int s[M];

int BinarySearch(int n,int s[],int x)
{
    int low=0,high=n-1;
    while(low<=high)
    {
        int middle=(low+high)/2;
        if(x==s[middle])
        {
            return middle;
        }
        else if(x>s[middle])
        {
            low=middle+1;
        }
        else
        {
            high=middle-1;
        }
    }
    return -1;
}

int main()
{
    while(cin>>n)
    {
        for(i=0; i<n; i++)
        {
            cin>>s[i];
        }
        sort(s,s+n);
        for(i=0; i<n; i++)
        {
            cout<<s[i]<<" ";
        }
        cout<<endl;
        cin>>x;
        i=BinarySearch(n,s,x);
        if(i==-1)
        {
            cout<<"meiyou"<<endl;
        }
        else
        {
            cout<<"di"<<i+1<<"wei"<<endl;
        }
    }
    return 0;
}