Submission #1245458

#	Time	Username	Problem	Language	Result	Execution time	Memory
1245458		badge881	Triple Jump (JOI19_jumps)	C++20	100 / 100	607 ms	85872 KiB

jumps

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

const int MAXN = 5e5 + 5;

int n, q, arr[MAXN];
ll answer[MAXN];
vector<pair<int, int>> queries[MAXN];

class SegmentTree
{
    vector<ll> tree, lazy, maxval;
    int size;

public:
    SegmentTree(int n, int *a)
    {
        size = n;
        tree.resize(n << 2);
        lazy.resize(n << 2);
        maxval.resize(n << 2);
        build(1, n, 1, a);
    }

    void build(int l, int r, int idx, int *a)
    {
        if (l == r)
        {
            maxval[idx] = a[l];
            return;
        }
        int m = (l + r) >> 1;
        build(l, m, idx << 1, a);
        build(m + 1, r, idx << 1 | 1, a);
        maxval[idx] = max(maxval[idx << 1], maxval[idx << 1 | 1]);
    }

    void push(int idx)
    {
        if (!lazy[idx])
            return;
        for (int d = 0; d < 2; ++d)
        {
            int child = idx << 1 | d;
            tree[child] = max(tree[child], lazy[idx] + maxval[child]);
            lazy[child] = max(lazy[child], lazy[idx]);
        }
        lazy[idx] = 0;
    }

    void update(int l, int r, ll val, int tl = 1, int tr = -1, int idx = 1)
    {
        if (tr == -1)
            tr = size;
        if (r < tl || tr < l)
            return;
        if (l <= tl && tr <= r)
        {
            tree[idx] = max(tree[idx], val + maxval[idx]);
            lazy[idx] = max(lazy[idx], val);
            return;
        }
        push(idx);
        int m = (tl + tr) >> 1;
        update(l, r, val, tl, m, idx << 1);
        update(l, r, val, m + 1, tr, idx << 1 | 1);
        tree[idx] = max(tree[idx << 1], tree[idx << 1 | 1]);
    }

    ll query(int l, int r, int tl = 1, int tr = -1, int idx = 1)
    {
        if (tr == -1)
            tr = size;
        if (r < tl || tr < l)
            return 0;
        if (l <= tl && tr <= r)
            return tree[idx];
        push(idx);
        int m = (tl + tr) >> 1;
        return max(query(l, r, tl, m, idx << 1),
                   query(l, r, m + 1, tr, idx << 1 | 1));
    }
};

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

    scanf("%d", &n);
    for (int i = 1; i <= n; ++i)
        scanf("%d", &arr[i]);

    scanf("%d", &q);
    for (int i = 1; i <= q; ++i)
    {
        int l, r;
        scanf("%d%d", &l, &r);
        queries[l].emplace_back(r, i);
    }

    SegmentTree seg(n, arr);

    stack<int> mono;
    for (int i = n; i >= 1; --i)
    {
        while (!mono.empty())
        {
            int j = mono.top();
            seg.update(2 * j - i, n, arr[i] + arr[j]);
            if (arr[j] <= arr[i])
                mono.pop();
            else
                break;
        }
        mono.push(i);
        for (auto [r, idx] : queries[i])
            answer[idx] = seg.query(i, r);
    }

    for (int i = 1; i <= q; ++i)
        printf("%lld\n", answer[i]);
}

Compilation message (stderr)

jumps.cpp: In function 'int main()':
jumps.cpp:91:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
jumps.cpp:93:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   93 |         scanf("%d", &arr[i]);
      |         ~~~~~^~~~~~~~~~~~~~~
jumps.cpp:95:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   95 |     scanf("%d", &q);
      |     ~~~~~^~~~~~~~~~
jumps.cpp:99:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   99 |         scanf("%d%d", &l, &r);
      |         ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 14 / 14
• Subtask 3: 27 / 27
• Subtask 4: 54 / 54