Submission #151372

#	Time	Username	Problem	Language	Result	Execution time	Memory
151372		theboatman	Bigger segments (IZhO19_segments)	C++17	0 / 100	2 ms	376 KiB

segments

#include <bits/stdc++.h>

#define y1 theboatman
#define make_struct(args...) {args}

using namespace std;

typedef long long ll;

const long long INF = 1e18 + 10;
const int inf = 1e9 + 10;
const int N = 1e6 + 10;

int dp[3000][3000];
vector <ll> pref;

ll get(int l, int r) {
    ll res = pref[r];

    return (l ? res - pref[l - 1] : res);
}

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

    int n;
    cin >> n;

    vector <int> a(n);
    for(int i = 0; i < n; i++) {
        cin >> a[i];
    }

    for(int i = 0; i < n; i++) {
        for(int j = 0; j < n; j++) {
            dp[i][j] = -inf;
        }
    }

    for(int i = 0; i < n; i++) {
        dp[0][i] = 1;
    }

    pref.resize(n);
    for(int i = 0; i < n; i++) {
        pref[i] = (i ? pref[i - 1] + a[i] : a[i]);
    }

    vector <int> line(n + 1, -inf);
    for(int i = 0; i < n; i++) {
        for(int j = i; j < n; j++) {
            int l = j + 1, r = n;
            while(l < r) {
                int c = (l + r) / 2;
                if (get(i, j) > get(j + 1, c)) {
                    l = c + 1;
                }
                else {
                    r = c;
                }
            }

            line[l] = max(line[l], dp[i][j] + 1);


            dp[i][j] = max(dp[i][j], line[i]);
        }
    }

    int ans = 0;
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < n; j++) {
            ans = max(ans, dp[i][j]);
        }
    }

    cout << ans << "\n";
    return 0;
}
/*
*/

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