题目描述

C++代码

样例

#include<iostream>
#include<string>
#include<vector>
using namespace std;
int main()
{
    int N;
    cin >> N;
    vector<string> vc;
    for (int i = 0; i <= N; i++)
    {
        string u;
        getline(cin, u);
        vc.push_back(u);
    }
    /*cout << "\n";
    for (int i = 0; i <= N; i++)
    {
        cout << vc[i] << endl;
    }*/
    string s;
    string q;
    int ans = 0;
    bool vis = true;
    for (int i=vc[1].size()-1;i>=0;i--)
    {
        s += vc[1][i];
        ans++;
        vis=true;
        for (int j = 2; j < vc.size(); j++)
        {
            int st=vc[j].size();
            if(st-ans>=0)
            {
                if (vc[j][st-ans] != vc[1][i])
                {
                    vis = false;
                    break;
                }
            }
            else{
                vis=false;
                break;
            }
        }
        if (!vis)
        {
            break;
        }
    }
    if(!vis)
    {
        if(s.size()>0)
        {
            s.pop_back();
        }
    }
    bool viss=false;
    for(int i=s.size()-1;i>=0;i--)
    {
        if((s[i]>='A'&&s[i]<='Z')||(s[i]>='a'&&s[i]<='z'))
        {
            viss=true;
            break;
        }
    }
    if(viss)
    {
        for (int i = s.size() - 1; i >= 0; i--)
        {
            cout << s[i];
        }
    }
    else{
        cout << "nai" << endl;
    }
    return 0;
}