Submission #1836461

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Source Code Expand

#include <bits/stdc++.h>

using namespace std;

int main(void) {
  int n, k;
  cin >> n >> k;

  vector<int> a(k);
  for (int i = 0; i < k; i++) {
    cin >> a[i];
    a[i]--;
  }
  sort(a.begin(), a.end());

  vector<string> s(n);
  for (int i = 0; i < n; i++) {
    cin >> s[i];
  }

  int p = 100010;
  vector<string> g[100010];
  for (int i = 0; i < n; i++) {
    string t = "";
    for (int j = 0; j < s[i].size(); j++) {
      g[i].push_back(t);
      t += s[i][j];
    }
    g[i].push_back(s[i]);
    if (*lower_bound(a.begin(), a.end(), i) != i) continue;
    p = min(p, (int)s[i].size());
  }

  string ans = "-1";
  for (int i = 0; i <= p; i++) {
    string t = s[a[0]].substr(0, i);
    bool can = true;
    for (int j = 0; j < n; j++) {
      if (j == a[0]) continue;
      if (*lower_bound(a.begin(), a.end(), j) == j) {
        can &= (g[j][i] == t);
      } else if (s[j].size() >= i) {
        can &= (g[j][i] != t);
      }
    }
    if (!can) continue;
    ans = t;
    break;
  }
  cout << ans << endl;

  return 0;
}

Submission Info

Judge Result