제출 #1136155

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1136155		mnbvcxz123	Bigger segments (IZhO19_segments)	C++20	100 / 100	61 ms	8264 KiB

segments

#include <bits/stdc++.h>

using namespace std;

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int N;
    cin >> N;
    vector<long long> pref(N + 1);
    for(int i = 1; i <= N; ++i){
        cin >> pref[i];
        pref[i] += pref[i - 1];
    }

    vector<int> dp(N + 1), pos(N + 1);

    for(int i = 1; i <= N; ++i){
        pos[i] = max(pos[i], pos[i - 1]);
        dp[i] = dp[pos[i]] + 1;

        //(pos[i], i] <= (i, x] with x minimum
        //=> pref[i] - pref[pos[i]] <= pref[x] - pref[i]
        //=> 2 * pref[i] - pref[pos[i]]; <= pref[x]

        int ub = lower_bound(pref.begin(), pref.end(), 2 * pref[i] - pref[pos[i]]) - pref.begin();
        if(ub < (int)pref.size()) pos[ub] = max(pos[ub], i);
    }

    cout << dp[N] << '\n';

    return 0;
}

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