Submission #990115

#	Time	Username	Problem	Language	Result	Execution time	Memory
990115		tch1cherin	Bigger segments (IZhO19_segments)	C++17	100 / 100	53 ms	17028 KiB

segments

#include <bits/stdc++.h>
using namespace std;

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  int N;
  cin >> N;
  vector<int> a(N);
  for (int &value : a) {
    cin >> value;
  }
  vector<long long> pref(N + 1);
  for (int i = 0; i < N; i++) {
    pref[i + 1] = pref[i] + a[i];
  }
  vector<long long> dp(N + 1);
  vector<int> opt(N + 1);
  deque<int> opt_cur, opt_old;
  for (int i = 1; i <= N; i++) {
    while (opt_cur.size() > 1 && dp[opt_cur[1]] + pref[opt_cur[1]] <= pref[i]) {
      opt_cur.pop_front();
    }
    while (opt_old.size() > 1 && dp[opt_old[1]] + pref[opt_old[1]] <= pref[i]) {
      opt_old.pop_front();
    }
    if (dp[opt_cur[0]] + pref[opt_cur[0]] <= pref[i]) {
      opt[i] = opt[i - 1] + 1;
      dp[i] = pref[i] - pref[opt_cur[0]];
      opt_old = opt_cur;
      opt_cur = {};
    } else {
      opt[i] = opt[i - 1];
      dp[i] = pref[i] - pref[opt_old[0]];
    }
    while (!opt_cur.empty() && dp[opt_cur.back()] + pref[opt_cur.back()] > dp[i] + pref[i]) {
      opt_cur.pop_back();
    }
    opt_cur.push_back(i);
  }
  cout << opt.back() << "\n";
}

• Subtask 1: 13 / 13
• Subtask 2: 14 / 14
• Subtask 3: 10 / 10
• Subtask 4: 36 / 36
• Subtask 5: 27 / 27