1077. Kuchiguse (20)

题目如下：

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

题目要求从一系列给定字符串中找出公共结尾，因为这个结尾将会被所有的字符串所共有，所以我们保存第一个输入的字符串，用它来和各个字符串比较，找出共同位置，一旦发现没有共同部分，立即返回nai，因为输入和输出流是分开的，所以我们提前返回得到的输出文件没有任何问题；如果发现了公共部分，就要进行保存，我们用一个suffix变量保存这个公共字串，当发现的公共部分长度比suffix小，说明公共部分缩短，应该更新，为了保证第一次的公共部分能够写入suffix，我们把suffix的值初始化为第一次输入。

对于有空格的输入，应该使用getline()，getline()有个问题是会吃掉上一行的回车作为一个空行，因此getline()之前如果有输入一定要getchar()吃掉那个回车再处理。

代码如下：

#include <iostream>
#include <stdio.h>
#include <string>
#include <vector>

using namespace std;

int main()
{
    int N;
    string temp,suffix,input;
    cin >> N;
    getchar();
    getline(cin,temp);
    suffix = temp;
    for(int i = 1; i < N; i++){
        getline(cin,input);
        int tempCur = temp.length() - 1;
        int inputCur = input.length() - 1;
        while(input[inputCur] == temp[tempCur]){
            inputCur--;
            tempCur--;
        }
        int len = temp.length() - tempCur - 1;
        if(len == 0){
            suffix = "nai";
            break;
        }
        if(suffix.length() > len){
            suffix = temp.substr(tempCur + 1);
        }
    }
    cout << suffix << endl;
    return 0;
}