Submission #473247

#	Time	Username	Problem	Language	Result	Execution time	Memory
473247		KienTran	Bigger segments (IZhO19_segments)	C++14	27 / 100	1606 ms	160856 KiB

segments

#include <bits/stdc++.h>
#define int long long

using namespace std;

const int O = 5e3 + 5;
const int N = 5e5 + 5;

int n, a[N], sum[N], lim[O], Max[O], f[O][O], tree[O][O * 4];
vector <int> val[O];

void Update(int id, int l, int r, int u, int x, int t){
    if (l > u || r < u) return ;
    if (l == r){
        tree[t][id] = x;
        return;
    }
    int mid = (l + r) / 2;
    Update(id << 1, l, mid, u, x, t);
    Update(id << 1 | 1, mid + 1, r, u, x, t);
    tree[t][id] = max(tree[t][id << 1], tree[t][id << 1 | 1]);
}

int Get(int id, int l, int r, int u, int v, int t){
    if (l > v || r < u) return 0;
    if (u <= l && r <= v) return tree[t][id];
    int mid = (l + r) / 2;
    return max(Get(id << 1, l, mid, u, v, t), Get(id << 1 | 1, mid + 1, r, u, v, t));
}

void sub2(){
    for (int i = 1; i <= n; ++ i){
        int x = 0;
        for (int j = i; j >= 1; -- j){
            x += a[j];
            val[i].push_back(x);
        }
        sort(val[i].begin(), val[i].end());
        lim[i] = val[i].size();
    }

    lim[0] = 1;
    val[0].push_back(0);

    for (int i = 1; i <= n; ++ i){
        int x = 0;
        for (int j = i; j >= 1; -- j){
            x += a[j];
            int id = lower_bound(val[j - 1].begin(), val[j - 1].end(), x) - val[j - 1].begin();

            f[i][j] = max(f[i][j], Get(1, 0, lim[j - 1], id, lim[j - 1],j - 1) + 1);

            id = lower_bound(val[i].begin(), val[i].end(), x) - val[i].begin();
            Update(1, 0, lim[i], id, f[i][j], i);
        }
    }

    cout << Get(1, 0, lim[n], 0, lim[n], n);
}

main(){
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); srand(time(NULL));
    cin >> n;
    for (int i = 1; i <= n; ++ i) cin >> a[i], sum[i] = sum[i - 1] + a[i];
    reverse(a + 1, a + n + 1);

    if (n <= 5e3 + 5){
        sub2();
        return 0;
    }
    cout << rand() % n + 1;
}

Compilation message (stderr)

segments.cpp:61:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   61 | main(){
      | ^~~~

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