PAT日志 1077

顽强的小白

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

题目解析

题目老长，虽然介绍了一大堆，但实际内容很简单，求几个句子的公共后缀。
其中涉及几个点：

• 输入问题，输入是要带空格的，因此不能用printf，PAT限制不能用gets(),最后我选用了getline()，也就是用了string容器。其实题目中还是尽量不要用string因为特别容易 超时。
• 公共后缀可以经过反转变成公共前缀，这里我用了algorithm头文件下的reverse()函数，很简单。
• 关于容器string的用法我掌握的不牢，经常翻书看，记不住呀~ 本题中用到的有length（）求string长度，以及string类型可以想加的特点，值得我记笔记的是string类型可以加char类型的。

代码实现

string s[105] ;
int main(){
 scanf("%d",&n);
 getchar();
 for(int i=0;i<n;++i){
  getline(cin,s[i]);
  int len=s[i].length();
  if(len<minLen) minLen=len;
  reverse(s[i].begin(),s[i].end());
 }
 string suffix;
 for(int i=0;i<minLen;++i){
  char tmp=s[0][i];
  int flag=1;
  for(int j=1;j<n;++j){
   if(s[j][i]!=tmp){
    flag=0;
    break;
   }
  }
  if(flag==0) break;
  else {
   suffix=suffix+tmp;
  }
 }
 int len =suffix.length();
 if(len!=0){
  reverse(suffix.begin(),suffix.end());
  cout<<suffix<<endl;
 }else{
  printf("nai");
 }
}