Submission #953796

#	Time	Username	Problem	Language	Result	Execution time	Memory
953796		nguyennh	Bootfall (IZhO17_bootfall)	C++14	13 / 100	1084 ms	436 KiB

bootfall

#include<bits/stdc++.h>
#define el '\n'
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
using namespace std ;

int n;

namespace sub_trau{
  // check whether existing a way to divide array into 2 parts with sum = x;
  void solve(){
    vector<int> a(n + 5);
    for ( int i = 1 ; i <= n ; i++ ) cin >> a[i];
    if (n & 1){
      cout << 0;
      return;
    }
    bool odd = false , even = false;
    for ( int i = 1 ; i <= n ; i++ ){
      odd |= (a[i] & 1);
      even |= (a[i] % 2 == 0);
    }
    if (odd && even){
      cout << 0;
      return;
    }
    int sum = accumulate(a.begin() + 1 , a.begin() + n + 1 , 0);
    vector<int> ans , candidates;
    for ( int i = 1 ; i <= n ; i++ ) candidates.push_back(a[i]);
    for ( int val = odd ? 1 : 2 ; val <= sum ; val += 2 ){
      int all = sum + val;
      candidates.push_back(val);
      bool check = true;
      for ( int turn = 0 ; turn < n + 1 ; turn++ ){
        int need = all - candidates[turn];
        if (need & 1){
          check = false;
          break;
        }
        deque<int> cur;
        for ( int j = 0 ; j < candidates.size() ; j++ ){
          if (j == turn) continue;
          cur.push_back(candidates[j]);
        }
        cur.push_front(-1);
        vector<vector<bool>> dp(n + 5 , vector<bool> (need / 2 + 5));
        dp[0][0] = 1;
        for ( int i = 1 ; i <= n ; i++ ){
          for ( int j = 0 ; j <= need / 2 ; j++ ){
            dp[i][j] = dp[i - 1][j];
            if (j >= cur[i] && dp[i - 1][j - cur[i]]){
              dp[i][j] = 1;
            }
          }
        }
        if (!dp[n][need / 2]){
          check = false;
          break;
        }
      }
      if (check) ans.push_back(val);
      candidates.pop_back();
    }
    cout << ans.size() << el;
    for ( auto x : ans ) cout << x << " ";
  }
}

int32_t main (){
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> n;
  sub_trau::solve();
}

Compilation message (stderr)

bootfall.cpp: In function 'void sub_trau::solve()':
bootfall.cpp:41:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |         for ( int j = 0 ; j < candidates.size() ; j++ ){
      |                           ~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 0 / 15
• Subtask 4: 0 / 16
• Subtask 5: 0 / 21
• Subtask 6: 0 / 35