提出 #28404397

---

ソースコード 拡げる

#ifndef LOCAL
#include <bits/stdc++.h>
using namespace std;
#define debug(...) 42
#else
#include "Debug.hpp"
#endif

class Task {
 public:
  void Perform() {
    Read();
    Solve();
  }
 
 private:
  int64_t x;  
  set<string> all;
  set<string> good;

  void Read() {
    cin >> x; 
  }

  void Pre() {
    for (int st = 0; st <= 9; ++st) {
      for (int len = 1; len <= 19; ++len) {
        all.insert(string(len, char('0' + st)));
      }
      for (int d = 1; d <= 9; ++d) {
        int prv = st;
        string num(1, char('0' + prv));
        while (prv + d <= 9 && int(num.size()) <= 19) {
          prv += d;
          num += char('0' + prv);
          all.insert(num);
        }
      }
    }
    for (auto s : all) {
      good.insert(Full(s));
      reverse(s.begin(), s.end());
      good.insert(Full(s));
    }
  }

  string Trim(string s) {
    string t;
    for (auto &ch : s) {
      if (t.empty() && ch == '0') {
        continue;
      }
      t += ch;
    }
    return t;
  }

  string Full(string s) {
    string t = s;
    while (int(t.size()) < 19) {
      t = "0" + t;
    }
    return t;
  }

  void Solve() {
    Pre();
    cout << Trim(*good.lower_bound(Full(to_string(x)))) << '\n';
  }
};
 
int main() {
  ios_base::sync_with_stdio(false), cin.tie(nullptr);
  Task t;
  t.Perform();
  return 0;
}

提出情報

ジャッジ結果