Submission #586086

#	Time	Username	Problem	Language	Result	Execution time	Memory
586086		MilosMilutinovic	Cigle (COI21_cigle)	C++14	100 / 100	240 ms	98512 KiB

cigle

/**
 *    author:  wxhtzdy
 *    created: 29.06.2022 21:43:16
**/
#include <bits/stdc++.h>
 
using namespace std;
 
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);  
  int n;
  cin >> n;
  vector<int> a(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  a[0] = 0;
  vector<long long> pref(n + 1);
  for (int i = 0; i < n; i++) {
    pref[i + 1] = pref[i] + a[i];
  }
  vector<vector<int>> dp(n + 1, vector<int>(n + 1));
  for (int l = 1; l <= n; l++) {
    int ptr = l - 1;
    long long t = pref[ptr] - pref[ptr - 1];
    auto Find = [&](long long x) {
      while (ptr > 1 && x > t) {
        ptr -= 1; 
        t += pref[ptr] - pref[ptr - 1];
      }
      return (x == t ? ptr : 0);
    }; 
    vector<int> pref_mx(n + 1);
    for (int i = 0; i < l; i++) {
      pref_mx[i + 1] = max(pref_mx[i], dp[i][l - 1]);
    }
    int ft = 0;
    for (int r = l; r <= n; r++) {
      dp[l][r] = dp[l][r - 1];
      if (l < r) {
        long long s = pref[r - 1] - pref[l - 1];
        int at = Find(s); 
        if (at >= 1) { 
          ft += 1;
          dp[l][r] = max(dp[l][r], ft + pref_mx[at]);
        }
      }
    }
  }
  int ans = 0;
  for (int i = 1; i <= n; i++) {
    ans = max(ans, dp[i][n]);
  }              
  cout << ans << '\n';
  return 0;
}

• Subtask 1: 9 / 9
• Subtask 2: 11 / 11
• Subtask 3: 13 / 13
• Subtask 4: 15 / 15
• Subtask 5: 52 / 52