The Japanese language is notorious for its sentence ending particles. Personal preference of such particles can be considered as a reflection of the speaker's personality. Such a preference is called "Kuchiguse" and is often exaggerated artistically in Anime and Manga. For example, the artificial sentence ending particle "nyan~" is often used as a stereotype for characters with a cat-like personality:

• Itai nyan~ (It hurts, nyan~)
• Ninjin wa iyada nyan~ (I hate carrots, nyan~)

Now given a few lines spoken by the same character, can you find her Kuchiguse?

Input Specification:

Each input file contains one test case. For each case, the first line is an integer N (2<=N<=100). Following are N file lines of 0~256 (inclusive) characters in length, each representing a character's spoken line. The spoken lines are case sensitive.

Output Specification:

For each test case, print in one line the kuchiguse of the character, i.e., the longest common suffix of all N lines. If there is no such suffix, write "nai".

Sample Input 1:

3

Itai nyan~

Ninjin wa iyadanyan~

uhhh nyan~

Sample Output 1:

nyan~

Sample Input 2:

3

Itai!

Ninjinnwaiyada T_T

T_T

Sample Output 2:

nai

思路

求输入的几个字符串的最长公共后缀。
用一个cmstr暂时记录最长公共后缀，然后对于每一个输入的新字符串循环比较更新就行。

代码

#include<iostream>

using namespace std;

int main()

{

    int N;

    cin >> N;

    string cmstr;

    getchar();

    for(int i = 0; i < N; i++)

    {

        string s;

        getline(cin,s);

        const int len = s.size();

        for(int j = 0; j < len/2; j++)

        {

            swap(s[j],s[len - j - 1]);

        }

        if(i == 0)

        {

            cmstr = s;

            continue;

        }

        else

        {

            int minlen = len > cmstr.size()?cmstr.size():len;

            for(int v = 0; v < minlen; v++)

            {

                if(cmstr[v] != s[v])

                {

                    cmstr = cmstr.substr(0,v);

                    break;

                }

            }

        }

    }

    if(cmstr.size() == 0)

        cout << "nai" <<endl;

    else

    {

        for(int i = cmstr.size() - 1;i >= 0;i--)

        {

            cout << cmstr[i];

        }

    }

}