제출 #1287671

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1287671		KickingKun	3단 점프 (JOI19_jumps)	C++20	100 / 100	476 ms	91988 KiB

jumps

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

#define ll long long
#define ull unsigned long long
#define ld long double
#define bigint __int128
#define emb emplace_back
#define pb push_back
#define pii pair <int, int>
#define fi first
#define se second
#define all(v) v.begin(), v.end()
#define Task ""

#define MASK(k) (1ull << k)
#define bitcnt(k) __builtin_popcount(k)
#define testBit(n, k) ((n >> k) & 1)
#define flipBit(n, k) (n ^ (1ll << k))
#define offBit(n, k) (n & ~MASK(k))
#define onBit(n, k) (n | (1ll << k))

template <class T> bool minimize(T &a, T b) {if (a > b) {a = b; return true;} return false;}
template <class T> bool maximize(T &a, T b) {if (a < b) {a = b; return true;} return false;}

const int N = 5e5 + 5, lim = 60, mod = 1e9 + 7;
const ll INF = 1e18;

int n, q, a[N];
int l[N], r[N];

namespace sub2 {
    int f[5005][5005];
    void solve() {
        for (int x = 1; x <= n - 2; x++) {
            for (int z = x + 2, y = x + 1, ma = a[y]; z <= n; z++) {
                while ((y + 1) * 2 <= x + z) maximize(ma, a[++y]);
                f[x][z] = a[x] + ma + a[z];
            }
        }

        for (int len = 4; len <= n; len++)
            for (int x = 1, z = len; z <= n; x++, z++)
                maximize(f[x][z], max(f[x][z - 1], f[x + 1][z]));

        for (int i = 1; i <= q; i++)
            cout << f[l[i]][r[i]] << '\n';
    }
}

namespace sub3 {
    int sufMa[N];
    vector <pii> candidate;

    void solve() {
        for (int i = n; i > 0; i--)
            sufMa[i] = max(sufMa[i + 1], a[i]);

        // nhung cap (a, b) : max(A[a+1, b-1]) < min(A[a], A[b])

        stack <int> st;
        for (int i = 1; i <= n; i++) {
            while (!st.empty() && a[st.top()] <= a[i]) {
                // neu truoc i ton tai k ma A[x] <= A[k] -> x da bi bo / neu ko thi A[x] lon nhat
                // den khi A[x] <= A[i] -> x va i la 2 dau mut lon nhat
                candidate.emplace_back(st.top(), i);
                st.pop();
            }

            if (!st.empty()) {
                // A[st.top()] > A[st.top() + 1 ... i]
                // cap nay co the chac chan thoa khi A[st.top] > A[i] > max o giua
                // nhung vi tri trong st con lai ko thoa vi co max_mid >= A[st.top()] > A[i]
                candidate.emplace_back(st.top(), i);
            }
            st.emplace(i);
        }

        int ans = 0;
        for (auto [x, y]: candidate) {
            int miZ = 2 * y - x;
            if (miZ <= n) maximize(ans, a[x] + a[y] + sufMa[miZ]);
        }
        cout << ans;
    }
}

namespace sub4 {
    struct Node {
        int mxF, mxA, mxAns;
        Node () {}
        Node (int a, int b, int c) {
            mxF = a; mxA = b; mxAns = c;
        }
        // l <= i <= j <= r -> mxAns = max(Fi + Aj)
        Node operator + (const Node &other) {
            Node res;
            res.mxF = max(mxF, other.mxF);
            res.mxA = max(mxA, other.mxA);
            res.mxAns = max({mxAns, other.mxAns, mxF + other.mxA});
            return res;
        }
    };

    struct SegmentTree {
        vector <Node> node;
        SegmentTree (int len) {
            node.assign(len * 4 + 1, Node());
        }

        void build(int id, int l, int r) {
            if (l == r) {
                node[id] = Node(0, a[l], a[l]);
                return;
            }
            int mid = (l + r) >> 1;
            build(id << 1, l, mid); build(id << 1 | 1, mid + 1, r);
            node[id] = node[id << 1] + node[id << 1 | 1];
        }

        void update(int id, int l, int r, int p, int f) {
            if (l == r) {
                maximize(f, node[id].mxF);
                node[id] = Node(f, a[l], f + a[l]);
                return;
            }
            int mid = (l + r) >> 1;
            if (p <= mid) update(id << 1, l, mid, p, f);
            else update(id << 1 | 1, mid + 1, r, p, f);
            node[id] = node[id << 1] + node[id << 1 | 1];
        }

        Node get(int id, int l, int r, int u, int v) {
            if (u > r || v < l) return Node(0, 0, 0);
            if (u <= l && r <= v) return node[id];
            int mid = (l + r) >> 1;
            return get(id << 1, l, mid, u, v) + get(id << 1 | 1, mid + 1, r, u, v);
        }
    };

    vector <int> candidate[N];
    vector <pii> query[N];

    void solve() {
        stack <int> st;
        for (int i = 1; i <= n; i++) {
            while (!st.empty() && a[st.top()] <= a[i]) {
                // neu truoc i ton tai k ma A[x] <= A[k] -> x da bi bo / neu ko thi A[x] lon nhat
                // den khi A[x] <= A[i] -> x va i la 2 dau mut lon nhat
                candidate[st.top()].emplace_back(i);
                st.pop();
            }

            if (!st.empty()) {
                // A[st.top()] > A[st.top() + 1 ... i]
                // cap nay co the chac chan thoa khi A[st.top] > A[i] > max o giua
                // nhung vi tri trong st con lai ko thoa vi co max_mid >= A[st.top()] > A[i]
                candidate[st.top()].emplace_back(i);
            }
            st.emplace(i);
        }

        for (int i = 1; i <= q; i++) {
            query[l[i]].emplace_back(r[i], i);
        }

        SegmentTree ST(n); vector <int> ans(q + 1);
        ST.build(1, 1, n);

        for (int l = n; l > 0; l--) {
            for (int b: candidate[l]) if (2 * b - l <= n) {
                 ST.update(1, 1, n, 2 * b - l, a[l] + a[b]);
            }
            for (auto [r, id]: query[l]) {
                ans[id] = ST.get(1, 1, n, l, r).mxAns;
            }
        }

        for (int i = 1; i <= q; i++)
            cout << ans[i] << '\n';
    }
}

int main() {
	ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);

	if (fopen(Task".inp", "r")) {
		freopen(Task".inp", "r", stdin);
		freopen(Task".out", "w", stdout);
	}

    cin >> n;
    for (int i = 1; i <= n; i++) cin >> a[i];
    cin >> q;
    for (int i = 1; i <= q; i++) cin >> l[i] >> r[i];

    if (n <= 5e3) sub2::solve();
    else if (q == 1 && l[1] == 1 && r[1] == n) sub3::solve();
    else sub4::solve();
}

컴파일 시 표준 에러 (stderr) 메시지

jumps.cpp: In function 'int main()':
jumps.cpp:188:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  188 |                 freopen(Task".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
jumps.cpp:189:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  189 |                 freopen(Task".out", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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