1121 Damn Single (25 分)

2019-05-02

1121 Damn Single (25 分)

“Damn Single (单身狗)” is the Chinese nickname for someone who is being single. You are supposed to find those who are alone in a big party, so they can be taken care of.

Input Specification:

Each input file contains one test case. For each case, the first line gives a positive integer N (≤ 50,000), the total number of couples. Then N lines of the couples follow, each gives a couple of ID’s which are 5-digit numbers (i.e. from 00000 to 99999). After the list of couples, there is a positive integer M (≤ 10,000) followed by M ID’s of the party guests. The numbers are separated by spaces. It is guaranteed that nobody is having bigamous marriage (重婚) or dangling with more than one companion.

Output Specification:

First print in a line the total number of lonely guests. Then in the next line, print their ID’s in increasing order. The numbers must be separated by exactly 1 space, and there must be no extra space at the end of the line.

Sample Input:

3
11111 22222
33333 44444
55555 66666
7
55555 44444 10000 88888 22222 11111 23333

Sample Output:

1 2	5 10000 23333 44444 55555 88888

作者: CHEN, Yue

单位: 浙江大学

时间限制: 200 ms

内存限制: 64 MB

代码长度限制: 16 KB

题目大意

给出情侣的名单以及聚会的名单，要求找出聚会中的单身狗。纯单身狗以及伴侣没出现的都算单身狗。

分析

用match数组保存情侣配对关系，map party记录聚会中出现的人。对于聚会上的每一个人，查找match数组得其情侣，然后在party中查找是否在场。

代码

#include <iostream>
#include <vector>
#include <stack>
#include <algorithm>
#include <deque>
#include <queue>
#include <map>
#include <set>
#include <cstring>
#include <cmath>
#include <sstream>

using namespace std;
int n,q,temp;
int match[100000];
map<int,int> party;
int main() {
    fill(match,match+100000,-1);
    cin>>n;
    int a,b;
    for(int i=0;i<n;i++){
        cin>>a>>b;
        match[a]=b;
        match[b]=a;
    }
    cin>>q;
    for(int i=0;i<q;i++){
        cin>>temp;
        party[temp]=1;
    }
    vector<int> single;
    for(auto it:party){
        if(match[it.first]==-1||party[match[it.first]]==0)
            single.push_back(it.first);
    }
    cout<<single.size()<<endl;
    for(int i=0;i<single.size();i++){
        if(i!=0)
            printf(" ");
        printf("%05d",single[i]);
    }
    return 0;
}

其他

这题最后不能输出多余空行，否则测试点1格式错误。然而1101 Quick Sort （25 分)里面必须输出空行。。无语了