1077. Kuchiguse (20) PAT甲级

#include<iostream>
#include<vector>
using namespace std;

vector<string> v;

int main(){
int N;
string s;
int minLen=300;
int count=0;
cin>>N;
//cin.sync();//清空缓冲区
getchar();
for(int i=0;i<N;i++){

getline(cin,s);
v.push_back(s);
int len=s.length();
if(len<minLen)  minLen=len;
for(int j=0;j<len/2;j++){
char temp=v[i][j];
v[i][j]=v[i][len-1-j];
v[i][len-1-j]=temp;
}

}

for(int i=0;i<minLen;i++){
char c=v[0][i];
bool same=true;
for(int j=1;j<v.size();j++){
if(c!=v[j][i]){
same=false;
break;
}
}
if(same)    count++;
else    break;
}
if(count){
for(int i=count-1;i>=0;i--){
cout<<v[0][i];
}
cout<<endl;
}
else    cout<<"nai"<<endl;

}