Submission #159075

#	Time	Username	Problem	Language	Result	Execution time	Memory
159075		mrboorger	Bigger segments (IZhO19_segments)	C++17	37 / 100	161 ms	95600 KiB

segments

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
//#include "interactive.h"

#define pb push_back
#define F first
#define S second
#define ll long long
#define ld long double
#define sqr(x) (x) * (x)
//#define all(a) a.begin(), a.end()

using namespace std;

const int maxn = 3005;
const ll inf = 1e18;

ll dp[maxn][maxn];
int a[maxn];
ll sum[maxn];
int mx[maxn];

ll f(int l, int r)
{
    return sum[r] - (l > 0 ? sum[l - 1] : 0);
}

int main()
{
#ifdef LOCAL
//    freopen("input.txt", "r", stdin);
//    freopen("output.txt", "w", stdout);
#endif // LOCAL
//    ios_base::sync_with_stdio(0);
//    cin.tie(0);
//    cout.tie(0);
    int n;
    cin >> n;
    for(int i = 0; i < n; ++i)
    {
        cin >> a[i];
        sum[i] = a[i] + (i > 0 ? sum[i - 1] : 0);
    }
    for(int i = 0; i < n; ++i)
        for(int j = 0; j <= i + 1; ++j)
            dp[i][j] = inf;
    dp[0][1] = a[0];
    mx[0] = 1;
    for(int i = 0; i < n - 1; ++i)
        for(int j = max(1, mx[i] - 2); j <= mx[i]; ++j)
    {
        if (dp[i][j] == inf) continue;
        dp[i + 1][j] = min(dp[i + 1][j], dp[i][j] + a[i + 1]);
        mx[i + 1] = max(mx[i + 1], j);
        {
            int l = i + 1, r = n - 1;
            int b = n + 1;
            while(l <= r)
            {
                int m = (l + r) / 2;
                if (f(i + 1, m) >= dp[i][j])
                {
                    b = min(b, m);
                    r = m - 1;
                }
                else
                {
                    l = m + 1;
                }
            }
            if (b < n + 1)
            {
                dp[b][j + 1] = min(dp[b][j + 1], f(i + 1, b));
                mx[b] = max(mx[b], j + 1);
            }
        }
    }
    int ans = 0;
    for(int j = 1; j <= n; ++j)
        if (dp[n - 1][j] != inf) ans = j;
    cout << ans << endl;
    return 0;
}

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