湖南大学第十五届程序设计竞赛（重现赛）：F题 （map与unordered_map）

湖南大学第十五届程序设计竞赛（重现赛）：F题 （map与unordered_map）

链接：https://ac.nowcoder.com/acm/contest/908/F
来源：牛客网

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题目描述

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AFei has many cards. Each card has a number written on it. Now he wants to takes some out of his card and puts them in a box. And he wants to know whether the card with the number x was in the box. So he has the following two operations：
0 x （It means to put a card with the number x in the box.）
1 x (It means to query if there is a card with the number x in the box.)

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输入描述:

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The first line of the input is an integer n (1 <= n <= 106), the number of operations. Next n lines represent n operations, and two integers k ( k∈{0,1}) and x (0<=x<=109) are separated by spaces on each line, as described above.

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输出描述:

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For each query, output one line “yes” if there is a card with the number x in the box, otherwise output one line “no”.

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示例1

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输入
5
0 1
1 2
0 2
1 3
1 2
输出
no
no
yes

题解：题意应该不难，就是有两种操作，每个操作对应两个数字，第一个数字如果是0，则相当于向容器中放值，如果为1，这就是查找操作
开始想着直接 用数字，然后在查找的时候用个二分，结果发现可能放进去的数的顺序可能不一样，于是就必须还得进行排序，当然结果不出意外TLE，后面就想着用map试试，结果就开始一顿猛操作，由于开始对map还不是用的太熟，于是就一边查资料，一边敲，最终发现好像用map好简单，下面是我的代码：

#include
using namespace std;
int main()
{
    map<int,int>mp;
    int t;
    scanf("%d",&t);
    while(t--)
    {
        int num1,num2;
        scanf("%d%d",&num1,&num2);
        if(num1==0)
        {
            mp.insert(make_pair(num2,num1));    //由于map是按键值排序，于是我选择把num2放在key值
        }
        else
        {
            if(mp.find(num2)==mp.end())             //这就是map比较强的地方所在，tcl
            {
                printf("no\n");
            }
            else
                printf("yes\n");
        }
    }
    return 0;
}

但是还是TLE，在牛客群里看了大佬的指点，说用unordered_map，于是又学了下unordered_map，结果发现自己没允许c++14编译，又在网上看了大佬的头文件提示，我是不知道啥意思，但是用unordered_map就A了。。。。

#include
#include
#if(__cplusplus == 201103L)
#include 
#include 
#else
#include 
#include 
namespace std
{
    using std::tr1::unordered_map;
    using std::tr1::unordered_set;
}
#endif
using namespace std;
int main()
{
    ios::sync_with_stdio(false);
    unordered_map<int,int>mp;
    int n;
    cin>>n;
    int num1,num2;
    while(n--)
    {
        cin>>num1>>num2;
        if(num1==0)
        {
            mp.insert(make_pair(num2,num1));
        }
        else
        {
            if(mp.find(num2)==mp.end())
                printf("no\n");
            else
                printf("yes\n");
        }
    }
    return 0;
}