Submission #1230711

#	Time	Username	Problem	Language	Result	Execution time	Memory
1230711		thieunguyenhuy	Rainforest Jumps (APIO21_jumps)	C++20	27 / 100	421 ms	51340 KiB

jumps

#ifndef hwe
    #include "jumps.h"
#endif

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

#define POPCOUNT(n) (__builtin_popcountll((n)))
#define CLZ(n) (__builtin_clzll((n)))
#define CTZ(n) (__builtin_ctzll((n)))
#define LOG(n) (63 - __builtin_clzll((n)))
#define BIT(n, i) (((n) >> (i)) & 1ll)
#define MASK(i) (1ll << (i))
#define FLIP(n, i) ((n) ^ (1ll << (i)))
#define ON(n, i) ((n) | MASK(i))
#define OFF(n, i) ((n) & ~MASK(i))

#define Int __int128
#define fi first
#define se second

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
typedef pair<long long, int> pli;
typedef pair<int, long long> pil;
typedef vector<pair<int, int>> vii;
typedef vector<pair<long long, long long>> vll;
typedef vector<pair<long long, int>> vli;
typedef vector<pair<int, long long>> vil;

template <class T1, class T2> bool maximize(T1 &x, T2 y) {
    if (x < y) {
        x = y;
        return true;
    }
    return false;
}
template <class T1, class T2> bool minimize(T1 &x, T2 y) {
    if (x > y) {
        x = y;
        return true;
    }
    return false;
}

template <class T> void remove_duplicate(vector<T> &ve) {
    sort (ve.begin(), ve.end());
    ve.resize(unique(ve.begin(), ve.end()) - ve.begin());
}

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
template <class T1, class T2> T1 random(T1 l, T2 r) {
    return uniform_int_distribution<T1>(l, r)(rng);
}
template <class T> T random(T r) {
    return rng() % r;
}

const int N = 2e5 + 5, LG = 20;
const int MOD = 1e9 + 7;
const int inf = 1e9;
const long long INF = 1e18;

int n;
int L[N][LG], R[N][LG], nxt[N][LG], pref[N];
vector<int> h;

int get(int l, int r) {
    return pref[r] - (l == 0 ? 0 : pref[l - 1]);
}

void init(int _n, vector<int> H) {
    n = _n, h = H;

    h.insert(h.begin(), inf);
    h.emplace_back(inf + 1);
    n += 2;

    stack<int> st;
    for (int i = 0; i < n; ++i) {
        while (!st.empty() && h[st.top()] < h[i]) st.pop();
        L[i][0] = (st.empty() ? 0 : st.top());
        st.emplace(i);
    }

    while (!st.empty()) st.pop();
    for (int i = n - 1; i >= 0; --i) {
        while (!st.empty() && h[st.top()] < h[i]) st.pop();
        R[i][0] = (st.empty() ? n - 1 : st.top());
        st.emplace(i);
    }

    for (int i = 0; i < n; ++i)
        nxt[i][0] = (h[L[i][0]] > h[R[i][0]] ? L[i][0] : R[i][0]);

    for (int i = 1; i < LG; ++i) for (int j = 0; j < n; ++j) {
        L[j][i] = L[L[j][i - 1]][i - 1];
        R[j][i] = R[R[j][i - 1]][i - 1];
        nxt[j][i] = nxt[nxt[j][i - 1]][i - 1];
    }

    pref[0] = (h[0] < h[1]);
    for (int i = 1; i + 1 < n; ++i)
        pref[i] = pref[i - 1] + (h[i] < h[i + 1]);
    pref[n - 1] = pref[n - 2];
}

int jump(int u, int v) {
    int ans = 0;
    for (int i = LG - 1; i >= 0; --i) {
        if (h[nxt[u][i]] <= h[v]) {
            u = nxt[u][i];
            ans += MASK(i);
        }
    }

    for (int i = LG - 1; i >= 0; --i) {
        if (h[L[u][i]] <= h[v]) {
            u = L[u][i];
            ans += MASK(i);
        }
        if (h[R[u][i]] <= h[v]) {
            u = R[u][i];
            ans += MASK(i);
        }
    }

    if (u == v) return ans;
    return inf;
}

int minimum_jumps(int a, int b, int c, int d) {
    ++a, ++b, ++c, ++d;

    int low = a, high = b, optL = -1, optR = -1;
    while (low <= high) {
        int mid = (low + high) >> 1;
        if (get(a, mid - 1) == mid - a) {
            if (h[mid] <= h[c]) low = (optL = mid) + 1;
            else high = mid - 1;
        }
        else high = mid - 1;
    }

    low = a, high = b;
    while (low <= high) {
        int mid = (low + high) >> 1;
        if (get(mid, b - 1) == 0) {
            if (h[mid] <= h[c]) high = (optR = mid) - 1;
            else low = mid + 1;
        }
        else low = mid + 1;
    }

    int ans = inf;
    if (optL != -1) minimize(ans, jump(optL, c));
    if (optR != -1) minimize(ans, jump(optR, c));

    return (ans == inf ? -1 : ans);
}

#ifdef hwe
signed main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);

    int n, q; cin >> n >> q;

    vector<int> h(n);
    for (auto &x : h) cin >> x;

    init(n, h);
    
    for (int _ = 0; _ < q; ++_) {
        int a, b, c, d; cin >> a >> b >> c >> d;
        cerr << minimum_jumps(a, b, c, d) << '\n';
    }

    return 0;
}
#endif

• Subtask 1: 4 / 4
• Subtask 2: 0 / 8
• Subtask 3: 0 / 13
• Subtask 4: 0 / 12
• Subtask 5: 23 / 23
• Subtask 6: 0 / 21
• Subtask 7: 0 / 19