PAT甲级——A1077 Kuchiguse

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). 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

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
using namespace std;
int N;
int main()
{
    cin >> N;
    string res = "", str;
    vector<string>v;
    int minL = 300;
    getchar();
    for (int i = 0; i < N; ++i)
    {
        getline(cin, str);        
        reverse(str.begin(), str.end());
        v.push_back(str);        
        minL = minL < str.length() ? minL : str.length();
    }
    bool flag = true;
    for (int i = 0; i < minL && flag; ++i)
    {        
        for (int j = 1; j < N && flag; ++j)
        {
            if (v[0][i] != v[j][i])
                flag = false;
        }
        if (flag)
            res += v[0][i];
    }
    reverse(res.begin(), res.end());
    if (res.length() == 0)
        cout << "nai" << endl;
    else
        cout << res << endl;

    return 0;
}