Submission #1680176

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Source Code Expand

#include <bits/stdc++.h>
#define REP(i,n) for(int i=0;i<(int)(n);i++)
#define ALL(x) (x).begin(),(x).end()
#define LL long long
#define pii pair<int,int>
#define pll pair<LL,LL>

using namespace std;

int main(){

    int N,K;cin>>N>>K;
    vector<string> S;
    set<int> A;
    vector<string> s;
    REP(i,K){
        int a;cin>>a;
        A.insert(--a);
    }
    REP(i,N){
        string _s;cin>>_s;
        S.push_back(_s);
        if(A.count(i))s.push_back(_s);
    }

    sort(ALL(s));
    sort(ALL(S));
    if(upper_bound(ALL(S),s[K-1]) - lower_bound(ALL(S),s[0]) !=K){
        cout<<-1<<endl;
        return 0;
    }

    string ans="";
    int index = 0;
    while(upper_bound(ALL(S),ans +(char)('z'+1))!=upper_bound(ALL(S),s[K-1]) || lower_bound(ALL(S),ans)!=lower_bound(ALL(S),s[0])){
        if(index>=s[0].size()){
            cout<<-1<<endl;
            return 0;
        }
        ans += s[0][index++];
    }

    cout<<ans<<endl;








    return 0;
}

Submission Info

Judge Result