无聊撸了一个，没啥技术含量，别吐槽。。

#include <iostream>

using namespace std;

int BinarySearch(int* nums,int key,int len);

int search(int* nums,int key,int L,int R);

int main()

{

    int *nums;

    int length;

    int keyNum;

    cout<<"请输入你希望的数字个数："<<endl;

    cin>>length;

    nums = new int[length];

    cout<<"请输入"<<length<<"个数:"<<endl;

    for(int i=0;i<length;i++)

        scanf("%d",&nums[i]);

    cout<<"输入你想找的数字：:"<<endl;

    while(cin>>keyNum){

        int result = BinarySearch(nums,keyNum,length);

        if(!(result==-1))

            cout<<"Position in array is: "<<result<<"\n"<<endl;

        else

            cout<<"Failed!"<<endl;

        delete[] nums;

        cout<<"请输入你希望的数字个数:"<<endl;

        cin>>length;

        nums = new int[length];

        cout<<"请输入"<<length<<"个数:"<<endl;

        for(int i=0;i<length;i++)

            scanf("%d",&nums[i]);

        cout<<"输入你想找的数字：:"<<endl;

    }

    return 0;

}

int BinarySearch(int* nums,int key,int len){ //仅作为用户入口

    return search(nums,key,0,len);

}

int search(int* nums,int key,int L,int R){

    int mid = (L+R)/2;

    if(nums[mid]==key) return mid;   //递归基

    if(nums[mid]>key)

        return search(nums,key,L,mid-1);

    else if(nums[mid]<key)

        return search(nums,key,mid+1,R);

    return -1;   //如果失败了返回-1

}

OVER