代码:
#include <cstdio>
#include <algorithm>
#include <vector>
#include <iostream>
#define min(a,b) (a) > (b)?(b):(a)
using namespace std;
int n, len = 9999999;
string s[105];
vector<char> v;
int main()
{
scanf("%d", &n);
getchar();
for(int i = 0; i < n; i++)
{
getline(cin, s[i]);
reverse(s[i].begin(), s[i].end());
len = min(len, s[i].length());
}
for(int i = 0; i < len; i++)
{
int flag = 1;
char temp = s[0][i];
for(int j = 1; j < n; j++)
{
if(s[j][i] != temp)
{
flag = 0;
break;
}
}
if(flag == 1)
{
v.push_back(temp);
}
else
{
break;
}
}
if(v.size() == 0)
{
printf("nai\n");
}
else
{
for(int i = v.size()-1; i >= 0; i--)
{
printf("%c", v[i]);
}
printf("\n");
}
return 0;
}