Submission #497667

#	Time	Username	Problem	Language	Result	Execution time	Memory
497667		Karliver	Rainforest Jumps (APIO21_jumps)	C++17	39 / 100	1197 ms	92492 KiB

jumps

    
#include <bits/stdc++.h>
#include "jumps.h"
#define FIXED_FLOAT(x)  std::fixed <<std::setprecision(20) << (x)
#define all(v) (v).begin(), (v).end()
using namespace  std;
#define forn(i,n) for (int i = 0; i < (n); ++i)
#define rforn(i, n) for(int i = (n) - 1;i >= 0;--i)
#define sz(x) (int)x.size()
#define ff first
#define se second
#define mp make_pair
using ll = long long;
int mod = (ll)1e9 + 7;
const int INF = 1e9 + 1;

const double eps = 1e-7;

template <class T> using V = vector<T>;  
template <class T> using VV = V<V<T>>;  
template<class T, size_t SZ> using AR = array<T, SZ>;
template<class T> using PR = pair<T, T>;
template <typename XPAX>
bool ckma(XPAX &x, XPAX y) {
    return (x < y ? x = y, 1 : 0);
}
template <typename XPAX>
bool ckmi(XPAX &x, XPAX y) {
    return (x > y ? x = y, 1 : 0);
}

V<int> g[200001];

int dis[200001];
const int L = 19;
int pl[200001];
int pr[200001];
int F[200001][L];
int W[200001][L];
int H[200001];
bool firstcase = 1;

int n;
V<int> S[200001 * 4];

void build(V<int> &a, int v, int tl, int tr) {
    if (tl == tr) {
        S[v] = {a[tl]};
    } else { 
        int tm = (tl + tr) / 2;
        build(a, v*2, tl, tm);
        build(a, v*2+1, tm+1, tr);
        merge(S[v*2].begin(), S[v*2].end(), S[v*2+1].begin(), S[v*2+1].end(),
              back_inserter(S[v]));
    }
}

int query(int v, int tl, int tr, int l, int r, int x) {
    if (l > r)
        return -1;
    if (l == tl && r == tr) {
        vector<int>::iterator pos = lower_bound(S[v].begin(), S[v].end(), x);
        if(pos != S[v].begin()) {
            pos--;
            return *pos;
        }
        return -1;
    }
    int tm = (tl + tr) / 2;
    return max(query(v*2, tl, tm, l, min(r, tm), x), 
               query(v*2+1, tm+1, tr, max(l, tm+1), r, x));
}

void init(int N, V<int> a) {
    for(auto &c : a)--c;
    forn(i, N) H[i] = a[i];
    n = N;
    build(a, 1, 0, N-1);
    H[N] = N;
    stack<int> st;
    forn(i, N) {
        while(sz(st) && H[st.top()] < H[i])
            st.pop();
        if(sz(st))g[i].push_back(st.top());
        pl[H[i]] = sz(st) ? H[st.top()] : N;
        st.push(i);
    }
    while(sz(st))st.pop();
    rforn(i, N) {
        while(sz(st) && H[st.top()] < H[i])
            st.pop();
        if(sz(st))g[i].push_back(st.top());
        pr[H[i]] = sz(st) ? H[st.top()] : N;
        st.push(i);
    }
    forn(i, N) {
        dis[i] = -1;
        firstcase &= (H[i] == i);
    }
    pl[N] = pr[N] = N;
    for(int i = 0;i <= N;++i) {
        F[i][0] = max(pl[i], pr[i]);
        W[i][0] = pr[i];
    }
    for(int j = 1;j < L;++j) {
        forn(i,N+1) {
            F[i][j] = F[F[i][j-1]][j-1];
            W[i][j] = W[W[i][j-1]][j-1];
        }
    }



}


int minimum_jumps(int A, int B, int C, int D) {
    if(firstcase)
        return C-B;
    if(A == B && C == D) {
        int ret =0 ;
        int f = H[A];
        int t = H[C];
        rforn(i, L) if(F[f][i] <= t) f = F[f][i], ret += 1 << i;
        rforn(i, L) if(W[f][i] <= t) f = W[f][i], ret += 1 << i;
        if(f != t)return -1;
        return ret;
    }
    if(C == D) {
        int t = H[C];
        int f = query(1, 0, n-1, A, B, t);
        if(f == -1)return -1;
        int ret = 0;
        rforn(i, L) if(F[f][i] <= t) f = F[f][i], ret += 1 << i;
        rforn(i, L) if(W[f][i] <= t) f = W[f][i], ret += 1 << i;
        if(f != t)return -1;
        return ret;
    }

    queue<int> q;
    V<int> clr;

    auto reset = [&]() {
        for(auto x : clr)
            dis[x] = -1;
    };

    for(int a = A;a <= B;++a) {
        q.push(a);
        dis[a] = 0;
        clr.push_back(a);
    }
    while(sz(q)) {
        int v = q.front();
        q.pop();
        if(C <= v && v <= D) {

            int rr = dis[v];
            reset();
            return rr;
        }
        for(auto c : g[v]) {
            if(dis[c] == -1) {
                dis[c] = dis[v]+1;
                q.push(c);
                clr.push_back(c);
            }
        }
    }
    reset();
    return -1;
}
/*
int main() {

    init(7, {3, 2, 1, 6, 4, 5, 7});
    cout << minimum_jumps(3, 4, 6, 6) << '\n';
}
*/

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