1077 Kuchiguse （20 分）

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

解析

題意是尋找一組字串中最大相同字尾，並輸出。如果沒有：則輸出‘nai’ 最大相同字尾：完全可以使用reverse_iterator反向迭代器。這樣思路就類似尋找最大相同字首。 Code:

#include<string>
#include<vector>
#include<iostream>
#include<utility>
using namespace std;
const string out = "nai";
int main()
{
	int N;
	cin >> N;
	getchar();
	vector<string> spoken(N);
	vector<string::reverse_iterator> it(N);
	string result;
	for (int i = 0; i < N; i++) {
		getline(cin,spoken[i]);
		it[i] = spoken[i].rbegin();
	}
	bool Continue = true;
	while (Continue) {
		auto first = it[0];
		for (int i = 0; i < N && Continue; i++) {
			if (it[i] == spoken[i].rend() || *first != *it[i]) {  //到尾巴了  或 不是最大字尾
				Continue = false;
				break;
			}
			it[i]++;
		}
		if(Continue)
			result = *first + result;
	}
	if (result.empty())
		cout << out;
	else
		cout << result;
}