• C. Perfect Keyboard


    Polycarp wants to assemble his own keyboard. Layouts with multiple rows are too complicated for him — his keyboard will consist of only one row, where all 2626 lowercase Latin letters will be arranged in some order.

    Polycarp uses the same password ss on all websites where he is registered (it is bad, but he doesn't care). He wants to assemble a keyboard that will allow to type this password very easily. He doesn't like to move his fingers while typing the password, so, for each pair of adjacent characters in ss, they should be adjacent on the keyboard. For example, if the password is abacaba, then the layout cabdefghi... is perfect, since characters a and c are adjacent on the keyboard, and a and b are adjacent on the keyboard. It is guaranteed that there are no two adjacent equal characters in ss, so, for example, the password cannot be password (two characters s are adjacent).

    Can you help Polycarp with choosing the perfect layout of the keyboard, if it is possible?

    Input

    The first line contains one integer TT (1T10001≤T≤1000) — the number of test cases.

    Then TT lines follow, each containing one string ss (1|s|2001≤|s|≤200) representing the test case. ss consists of lowercase Latin letters only. There are no two adjacent equal characters in ss.

    Output

    For each test case, do the following:

    • if it is impossible to assemble a perfect keyboard, print NO (in upper case, it matters in this problem);
    • otherwise, print YES (in upper case), and then a string consisting of 2626 lowercase Latin letters — the perfect layout. Each Latin letter should appear in this string exactly once. If there are multiple answers, print any of them.
    Example
    input
    Copy
    5
    ababa
    codedoca
    abcda
    zxzytz

    abcdefghijklmnopqrstuvwxyza
    output
    Copy
    YES
    bacdefghijklmnopqrstuvwxyz
    YES
    edocabfghijklmnpqrstuvwxyz
    NO
    YES
    xzytabcdefghijklmnopqrsuvw
    NO
    

    有两种情况不可行:一个字母相邻字符数大于2的不可以;构成环的不可以
    符合的就是一条链
    从链的端点开始输出即可。
    #include <bits/stdc++.h>
    #define ll              long long
    #define PII             pair<int, int>
    #define rep(i,a,b)      for(int  i=a;i<=b;i++)
    #define dec(i,a,b)      for(int  i=a;i>=b;i--)
    using namespace std;
    int dir[4][2] = { { 0,1 } ,{ 0,-1 },{ 1,0 },{ -1,0 } };
    const long long INF = 0x7f7f7f7f7f7f7f7f;
    const int inf = 0x3f3f3f3f;
    const double pi = 3.14159265358979323846;
    const int mod = 998244353;
    const int N = 1e5+5;
    inline ll read()
    {
        ll x = 0; bool f = true; char c = getchar();
        while (c < '0' || c > '9') { if (c == '-') f = false; c = getchar(); }
        while (c >= '0' && c <= '9') x = (x << 1) + (x << 3) + (c ^ 48), c = getchar();
        return f ? x : -x;
    }
    ll gcd(ll m, ll n)
    {
        return n == 0 ? m : gcd(n, m%n);
    }
    ll lcm(ll m, ll n)
    {
        return m*n / gcd(m, n);
    }
    
    int main()
    {
        int T;
        cin>>T;
        while(T--)
        {
            string s;
            cin>>s;
            map<char,bool> vis;
            for(int i=0;i<26;i++)
            {
                vis[i+'a']=0;
            }
            map<char,set<char>> mp;
            int fg=0;
            for(int i=0;i<s.size();i++)
            {
                if(i-1>=0)
                    mp[s[i]].insert(s[i-1]);
                if(i+1<s.size())
                    mp[s[i]].insert(s[i+1]);
                if(mp[s[i]].size()>2)
                {
                    fg=1;
                    break;
                }
            }
            if(fg)
            {
                cout<<"NO"<<endl;
                continue;
            } else{
                string res;
    
                char st='A';
                for(auto i:mp)
                {
                    if(i.second.size()<=1)
                    {
                        st=i.first;
                        break;
                    }
                }
                if(st=='A')
                {
                    cout<<"NO"<<endl;
                    continue;
                }
                cout<<"YES"<<endl;
                vis[st]=1;
                for(int i=0;i<mp.size();i++)
                {
                    cout<<st;
                    for(auto j:mp[st])
                    {
                        if(!vis[j])
                        {
                            st=j;
                            vis[st]=1;
                        }
                    }
                }
                for(auto i:vis)
                {
                    if(i.second==0)
                        cout<<i.first;
                }
                cout<<endl;
            }
        }
        return 0;
    }
  • 相关阅读:
    jQuery Ajax 实例
    jQuery Ajax 实例
    mysql中使用MySqlParameter操作数据库
    mysql中使用MySqlParameter操作数据库
    MySQL limit 分页查询数据库
    html5新特性data_*自定义属性使用
    CSS中zoom和scale的区别
    Linux下nginx编译安装教程和编译参数详解
    nginx.conf配置
    linux下tar.gz、tar、bz2、zip等解压缩、压缩命令小结
  • 原文地址:https://www.cnblogs.com/dealer/p/12939489.html
Copyright © 2020-2023  润新知