Codeforces Round 486 Div3（包含前五题题解）

63 阅读 0 评论 42 点赞

我是靠谱客的博主开放棒球，最近开发中收集的这篇文章主要介绍Codeforces Round 486 Div3（包含前五题题解），觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

第一次打cf的div3耶，然后发现挺简单的，题目意思特别好懂，然后前三个题比较简单，其实第四题也简单，后两个题目稍微麻烦点，然后这次我只做了三题，第四题写完了结果没时间提交了，哎，还是不行，要继续加油啊。

There are $n$ students in a school class, the rating of the $i$ -th student on Codehorses is $a_{i}$ . You have to form a team consisting of $k$ students ( $1 \leq k \leq n$ ) such that the ratings of all team members are distinct.

If it is impossible to form a suitable team, print "NO" (without quotes). Otherwise print "YES", and then print $k$ distinct numbers which should be the indices of students in the team you form. If there are multiple answers, print any of them.

Input

The first line contains two integers $n$ and $k$ ( $1 \leq k \leq n \leq 100$ ) — the number of students and the size of the team you have to form.

The second line contains $n$ integers $a_{1}, a_{2}, \dots, a_{n}$ ( $1 \leq a_{i} \leq 100$ ), where $a_{i}$ is the rating of $i$ -th student.

Output

If it is impossible to form a suitable team, print "NO" (without quotes). Otherwise print "YES", and then print $k$ distinct integers from $1$ to $n$ which should be the indices of students in the team you form. All the ratings of the students in the team should be distinct. You may print the indices in any order. If there are multiple answers, print any of them.

Assume that the students are numbered from $1$ to $n$ .

   Examples 
 
     input 
    
      Copy 
    
5 3
15 13 15 15 12

     output 
    
      Copy 
    
YES
1 2 5 

     input 
    
      Copy 
    
5 4
15 13 15 15 12

     output 
    
      Copy 
    
NO

     input 
    
      Copy 
    
4 4
20 10 40 30

     output 
    
      Copy 
    
YES
1 2 3 4

Note

All possible answers for the first example:

{1 2 5}
{2 3 5}
{2 4 5}

Note that the order does not matter.

A题题意：给你一个序列，问你能否从中找到k个不同的数，那么就是一个大水题了，可以开一个数组记录，也可以用STL的set记录。

#include<iostream>
#include<cstdio>
#include<queue>
#include<cstring>
#include<algorithm>
#include<list>
#define inf 0x3f3f3f3f
using namespace std;
typedef long long ll;
int judge[1005];
int main()
{
    int n,k;
    memset(judge,0,sizeof judge);
    cin>>n>>k;
    int item;
    vector<int> v;
    int cnt = 0;
    for( int i =1  ;i <= n ; i++ )
        {
            cin>>item;
            if( judge[item] == 0 )
            {
                cnt++;
                judge[item]=  1;
                v.push_back(i);    //记录答案
            }
        }
    if( cnt >= k )
    {
        cout<<"YESn";
        for( int i = 0 ; i < k ; i++ )
        {
            if( i )
                cout<<" ";
            cout<<v[i];

        }
        cout<<endl;
    }
    else cout<<"NOn";
    return 0;
}

You are given $n$ strings. Each string consists of lowercase English letters. Rearrange (reorder) the given strings in such a way that for every string, all strings that are placed before it are its substrings.

String $a$ is a substring of string $b$ if it is possible to choose several consecutive letters in $b$ in such a way that they form $a$ . For example, string "for" is contained as a substring in strings "codeforces", "for" and "therefore", but is not contained as a substring in strings "four", "fofo" and "rof".