*blue jeans<pku 3080>

// 难道这题是让我们复习string用法...

Source Code

Problem: 3080  User: eth1 
Memory: 744K  Time: 63MS 
Language: G++  Result: Accepted 

Source Code 
#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <map>

using namespace std;
string f[15];
int n;
void solve()
{
    string tem,ans[61];
    int flag=0,i,m;
    for(i=60;i>=1;i--)
    {
        m=0;
        for(int j=0;j+i<=60;j++)
        {
            tem = f[0].substr(j,i);
            int k;
            for(k=1;k<n;k++)
            {
                if(f[k].find(tem)==-1)
                {
                    break;
                }
            }
            if(k==n) {flag=1;ans[m++]=tem;}
        }
        if(flag) break;
    }
    if(i<3) {cout<<"no significant commonalities"<<endl;return;}
    sort(ans,ans+m);
    cout<<ans[0]<<endl;
}
int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        cin>>n;
        for(int i=0;i<n;i++)
        cin>>f[i];
        solve();
    }
    return 0;
}