Submission #2501324

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Source Code Expand

#include <cstdio>
#include <vector>
#include <algorithm>
#include <unordered_map>
#include <string>
#include <cstdlib>
#include <iostream>
#include <cmath>

using namespace std;

struct S {
  decltype(begin(string())) b,e;
};

int main() {
  string s;
  cin >> s;
  int k;
  cin >> k;

  vector<S> bests;

  for(int i=0; i<s.size(); ++i) {
    for(int j=i+1; j<s.size()+1 && j<i+6; ++j) {
      auto b = s.begin()+i;
      auto e = s.begin()+j;
      if(bests.empty()) {
        bests.push_back({b, e});
      }
      int sk=bests.size();
      for(int k=min(size_t(4),bests.size()-1); k>=0; --k) {
        if(lexicographical_compare(b, e, bests[k].b, bests[k].e)) {
          sk = k;
        } else if(equal(b, e, bests[k].b, bests[k].e)) {
          goto lend;
        } else {
          break;
        }
      }
      if(sk>=0) bests.insert(begin(bests)+sk, {b, e});
      if(bests.size()>5) bests.erase(begin(bests)+5, end(bests));

      lend: 0;

    }
  }
  /*
  for(auto best:bests) {
    cout << string(best.b, best.e) << endl;
  }
  */
  cout << string(bests[k-1].b, bests[k-1].e) << endl;
}

Submission Info

Judge Result