Submission #1266114

#	Time	Username	Problem	Language	Result	Execution time	Memory
1266114		rayan_bd	Bigger segments (IZhO19_segments)	C++20	13 / 100	0 ms	328 KiB

segments

#include <bits/stdc++.h>
using namespace std;
#define int long long
const int mxN = 5e5 + 100;
int a[mxN], pref[mxN];
pair<int, int> dp[mxN];
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(nullptr); cout.tie(nullptr);
    int n;
    cin >> n;
    pref[0] = 0;
    vector<int> a(n + 1, 0), pref(n + 5, 0);
    for(int i = 1; i <= n; ++i){
        dp[i] = {-1, -1};
    }
    dp[0] = {0, 0};
    for(int i = 1; i <= n; ++i){
        cin >> a[i];
        pref[i] = pref[i - 1] + a[i];
    }
    auto query = [&](int l, int r){
        if(l == 0) return pref[r];
        return pref[r] - pref[l - 1];
    };
    auto _mrg = [&](int i, int j){
        if(dp[i].first == dp[j].first + 1) dp[i] = min(dp[i], {dp[j].first + 1, query(j + 1, i)});
        else dp[i] = max(dp[i], {dp[j].first + 1, query(j + 1, i)});
    };
    for(int i = 1; i <= n; ++i){
        dp[i] = dp[i - 1];
        dp[i].second += a[i];
        int st = 1, en = i, best = -1;
        while(st <= en){
            int mid = st + (en - st) / 2;
            if(dp[mid - 1].second <= query(mid, i)){
                best = mid - 1;
                st = mid + 1;
            }else{
                en = mid - 1;
            }
        }
        if(best > -1) _mrg(i, best);
    }
    cout << dp[n].first << "\n";

    return 0;
}

• Subtask 1: 13 / 13
• Subtask 2: 0 / 14
• Subtask 3: 0 / 10
• Subtask 4: 0 / 36
• Subtask 5: 0 / 27