PAT 1077. Kuchiguse (20)

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

找到每个字符串都有的后缀，从每个字符串的最后开始检查

#include <stack>
#include <cstring>
#include <iostream>
#include <vector>

using namespace std;

stack<char> suffix(vector<string> v) {
    stack<char> s;
    for (auto i = v[0].rbegin(); i != v[0].rend(); i++) {
        s.push(*i);
        for (int j = 1; j < v.size(); j++) {
            if (v[j].size() >= s.size() && v[j][v[j].size() - s.size()] != s.top()) {
                s.pop();
                return s;
            }
        }
    }
    return s;
}

int main() {
    int n = 0;
    cin >> n;
    getchar();
    vector<string> v(n);
    for (int i = 0; i < n; i++) {
        getline(cin, v[i]);
    }
    stack<char> s = suffix(v);
    if (s.size() == 0) {
        cout << "nai";
    }
    while (s.size() != 0) {
        cout << s.top();
        s.pop();
    }
    return 0;
}