Submission #1083138

#	Time	Username	Problem	Language	Result	Execution time	Memory
1083138		Tymond	Rainforest Jumps (APIO21_jumps)	C++17	4 / 100	723 ms	58172 KiB

jumps

#include <bits/stdc++.h>
#include "jumps.h"
using namespace std;
using ll = long long;
using ld = long double;
#define fi first
#define se second
#define vi vector<int>
#define vll vector<long long>
#define pii pair<int, int>
#define pll pair<long long, long long>
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());
inline int rand(int l,int r){return uniform_int_distribution<int>(l, r)(rng);}
inline ll rand(ll l,ll r){return uniform_int_distribution<ll>(l, r)(rng64);}
#ifdef DEBUG
auto&operator<<(auto&o,pair<auto,auto>p){return o<<"("<<p.first<<", "<<p.second<<")";}
auto operator<<(auto&o,auto x)->decltype(x.end(),o){o<<"{";int i=0;for(auto e:x)o<<","+!i++<<e;return o<<"}";}
#define debug(X...)cerr<<"["#X"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(X)
#else
#define debug(...){}
#endif

struct custom_hash {
    static uint64_t splitmix64(uint64_t x) {
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }

    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};

const int MAXN = 5e5 + 7;
const int MAXK = 22;
int lg[MAXN];
int mx[MAXK][MAXN];
int jumpL[MAXK][MAXN];
int jumpP[MAXK][MAXN];
int tab[MAXN];
int n;
bool distCount = 0;

int getMx(int l, int p){
    if(p < l){
        return 0;
    }
    return max(mx[lg[p - l + 1]][l], mx[lg[p - l + 1]][p - (1 << lg[p - l + 1]) + 1]);
}

int getMxP(int ind){
    if(getMx(ind + 1, n - 1) <= tab[ind]){
        return -1;
    }

    int l = ind + 1;
    int p = n - 1;
    int s;
    while(l < p){
        s = (l + p) / 2;
        if(getMx(ind + 1, s) <= tab[ind]){
            l = s + 1;
        }else{
            p = s;
        }
    }
    return l;
}

int getMxL(int ind){
    if(getMx(0, ind - 1) <= tab[ind]){
        return -1;
    }

    int l = 0;
    int p = ind - 1;
    int s;
    while(l < p){
        s = (l + p + 1) / 2;
        if(getMx(s, ind - 1) <= tab[ind]){
            p = s - 1;
        }else{
            l = s;
        }
    }
    return l;
}

void init(int N, vi H) {
    n = N;
    bool f = 1;
    for(int i = 0; i < n; i++){
        tab[i] = H[i];
        if(tab[i] != i + 1){
            f = 0;
        }
    }

    if(f){
        distCount = 1;
        return;
    }

    for(int i = 2; i < MAXN; i++){
        lg[i] = lg[i / 2] + 1;
    }

    for(int i = 0; i < n; i++){
        mx[0][i] = tab[i];
    }

    for(int j = 1; j < MAXK; j++){
        for(int i = 0; i < n; i++){
            mx[j][i] = max(mx[j - 1][i], mx[j - 1][min(n - 1, i + (1 << (j - 1)))]);
        }
    }

    for(int i = 0; i < n; i++){
        jumpL[0][i] = getMxL(i);
        jumpP[0][i] = getMxP(i);
    }

    for(int j = 1; j < MAXK; j++){
        for(int i = 0; i < n; i++){
            if(jumpL[j - 1][i] != -1){
                jumpL[j][i] = jumpL[j - 1][jumpL[j - 1][i]];
            }else{
                jumpL[j][i] = -1;
            }

            if(jumpP[j - 1][i] != -1){
                jumpP[j][i] = jumpP[j - 1][jumpP[j - 1][i]];
            }else{
                jumpP[j][i] = -1;
            }
        }
    }
}

int dist(int a, int b){
    int ans = 1e9;
    int akt = a;
    int res = 0;
    for(int j = MAXK - 1; j >= 0; j--){
        if(jumpP[j][akt] != -1 && jumpP[j][akt] < b){
            akt = jumpP[j][akt];
            res += (1 << j);
        }
    }
    res++;
    akt = jumpP[0][akt];
    if(akt == b){
        ans = res;
    }

    if(getMx(0, a - 1) > tab[a]){
        res = 0;
        akt = a;

        int l = 0;
        int p = a - 1;
        int s;
        while(l < p){
            s = (l + p) / 2;
            if(getMx(s, a - 1) <= tab[a]){
                p = s - 1;
            }else if(getMx(s, a - 1) >= tab[b]){
                l = s + 1;
            }else{
                p = s;
            }
        }

        if(tab[l] > tab[a] && tab[l] < tab[b]){
            for(int j = MAXK - 1; j >= 0; j--){
                if(jumpL[j][akt] != -1 && jumpL[j][akt] > l){
                    akt = jumpL[j][akt];
                    res += (1 << j);
                }
            }
            res++;
            akt = jumpL[0][akt];
            if(akt == l){
                for(int j = MAXK - 1; j >= 0; j--){
                    if(jumpP[j][akt] != -1 && jumpP[j][akt] < b){
                        akt = jumpP[j][akt];
                        res += (1 << j);
                    }
                }
                res++;
                akt = jumpP[0][akt];
                if(akt == b){
                    ans = min(ans, res);
                }
            }
        }
    }

    if(ans == 1e9){
        return -1;
    }
    return ans;
}

int minimum_jumps(int A, int B, int C, int D){
    if(distCount){
        return C - B;
    }
    if(getMx(B + 1, C - 1) >= getMx(C, D)){
        return -1;
    }

    if(A == B && C == D){
        return dist(A, C);
    }

    vi dist(n, 1e9);
    queue<int> q;
    vi vis(n, 0);
    for(int i = A; i <= B; i++){
        vis[i] = 1;
        q.push(i);
        dist[i] = 0;
    }

    while(sz(q)){
        int v = q.front();
        q.pop();

        int akt = getMxL(v);
        if(akt != -1 && !vis[akt]){
            q.push(akt);
            vis[akt] = 1;
            dist[akt] = dist[v] + 1;
        }

        akt = getMxP(v);
        if(akt != -1 && !vis[akt]){
            q.push(akt);
            vis[akt] = 1;
            dist[akt] = dist[v] + 1;
        }
    }

    int ans = 1e9;
    for(int i = C; i <= D; i++){
        ans = min(ans, dist[i]);
    }
    if(ans == 1e9){
        return -1;
    }
    return ans;
}

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