Submission #1204969

#	Time	Username	Problem	Language	Result	Execution time	Memory
1204969		ofoz	Bigger segments (IZhO19_segments)	C++17	37 / 100	1596 ms	21456 KiB

segments

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

#define int long long

vector<int> a;
vector<int> prfx;
vector< vector<int> > memo;

// Compute prefix sum from l to r
int getPrfx(int l, int r) {
    int left = (l == 0) ? 0 : prfx[l - 1];
    int right = prfx[r];
    return right - left;
}

// Custom comparison function
bool compare(const vector<int>& s1, const vector<int>& s2) {
    if (s1[0] > s2[0]) return true;
    if (s1[0] < s2[0]) return false;
    return s1[1] < s2[1];
}

// DP function
vector<int> dp(int i) {
    if (i < 0) return vector<int>{1, 0};
    if (memo[i][0] != -1) return memo[i];

    vector<int> res = dp(i - 1);
    res[1] += a[i];

    for (int j = 0; j < i; ++j) {
        vector<int> c = dp(j);
        int s = getPrfx(j + 1, i);
        if (s < c[1]) continue;

        c[1] = s;
        c[0] += 1;

        if (compare(c, res)) res = c;
    }

    memo[i] = res;
    return res;
}

signed main() {
    int n;
    cin >> n;

    a.resize(n);
    for (int i = 0; i < n; ++i) cin >> a[i];

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

    memo.assign(n, vector<int>(2, -1));

    vector<int> result = dp(n - 1);
    cout << result[0] << endl;

    return 0;
}

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