Submission #415875

#	Time	Username	Problem	Language	Result	Execution time	Memory
415875		valerikk	Rainforest Jumps (APIO21_jumps)	C++17	33 / 100	4097 ms	5812 KiB

jumps

#include <bits/stdc++.h>

using namespace std;

const int N = 2e5 + 7;
const int INF = 1e9;

int n, h[N];
int l[N], r[N], m[N];

void init(int nn, vector<int> hh) {
    for (int i = 0; i < nn; i++) h[i + 1] = hh[i] - 1;
    h[0] = nn;
    h[nn + 1] = nn + 1;
    n = nn + 2;
    vector<int> st;
    for (int i = 0; i < n; ++i) {
        while (!st.empty() && h[st.back()] < h[i]) {
            r[st.back()] = i;
            st.pop_back();
        }
        st.push_back(i);
    }
    r[n - 1] = n - 1;
    st.clear();
    for (int i = n - 1; i >= 0; --i) {
        while (!st.empty() && h[st.back()] < h[i]) {
            l[st.back()] = i;
            st.pop_back();
        }
        st.push_back(i);
    }
    l[0] = 0;
    st.clear();
    for (int i = 0; i < n; ++i) m[i] = h[l[i]] > h[r[i]] ? l[i] : r[i];
}

int minimum_jumps(int aa, int bb, int cc, int dd) {
    int a = aa + 1, b = bb + 1, c = cc + 1, d = dd + 1;
    int mx = 0;
    for (int i = c; i <= d; ++i) mx = max(mx, h[i]);
    int mx1  = -INF;
    for (int i = b + 1; i < c; ++i) mx1 = max(mx1, h[i]);
    if (mx1 > mx || h[b] > mx) return -1;
    for (int i = a; i <= b; ++i) {
        if (h[i] > mx) a = max(a, i + 1);
    }
    int st = b;
    for (int i = a; i <= b; ++i) {
        if (h[i] < mx && h[i] > h[st]) st = i;
    }
    int res = 1;
    while (h[st] < mx1) {
        ++res;
        //cout << st - 1 << " " << h[st] + 1 << endl;
        if (h[m[st]] < mx) st = m[st]; else st = r[st];
    }
    //cout << st - 1 << " " << h[st] + 1 << endl;
    return res;
}

int get_ans(int a, int b, int c, int d) {
    ++a, ++b, ++c, ++d;
    vector<int> dist(n, INF);
    queue<int> q;
    for (int i = a; i <= b; ++i) {
        dist[i] = 0;
        q.push(i);
    }
    while (!q.empty()) {
        int v = q.front();
        q.pop();
        if (v >= c && v <= d) return dist[v];
        for (auto u : {l[v], r[v]}) {
            if (dist[v] +1 < dist[u]) {
                dist[u] = dist[v] + 1;
                q.push(u);
            }
        }
    }
    return -1;
}

#ifdef LOCAL

int main() {
    freopen("input.txt", "r", stdin);
    ios::sync_with_stdio(false);
    cin.tie(0);
    if (0) {
        int nn, qq;
        cin >> nn >> qq;
        vector<int> hh(nn);
        for (auto &x : hh) cin >> x;
        init(nn, hh);
        while (qq--) {
            int aa, bb, cc, dd;
            cin >> aa >> bb >> cc >> dd;
            cout << minimum_jumps(aa, bb, cc, dd) << endl;
        }
    } else {
        srand(0);
        int nn = 15;
        vector<int> hh(nn);
        for (int i = 0; i < nn; ++i) hh[i] = i + 1;
        random_shuffle(hh.begin(), hh.end());
        init(nn, hh);
        int qq = 1000000;
        while (qq--) {
            vector<int> v;
            for (int i = 0; i < 4; ++i) v.push_back(rand() % nn);
            sort(v.begin(), v.end());
            if (v[1] == v[2]) continue;
            int a = v[0], b = v[1], c = v[2], d = v[3];
            int ans = get_ans(a, b, c, d);
            int ans1 = minimum_jumps(a, b, c, d);
            if (ans != ans1) {
                cout << nn << endl;
                for (auto i : hh) cout << i << " ";
                cout << endl << a << " " << b << " " << c << " " << d << endl;
                cout << ans << " " << ans1 << endl;
                return 0;
            }
        }
    }
    return 0;
}

#endif

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