Submission #1202976

#	Time	Username	Problem	Language	Result	Execution time	Memory
1202976		lrnnz	Rainforest Jumps (APIO21_jumps)	C++20	21 / 100	4032 ms	44256 KiB

jumps

#include <bits/stdc++.h>
#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include "jumps.h"
using namespace std;
 
#define all(a) (a).begin(), (a).end()
#define sz(a) (int)(a).size()
#define ll long long
#define ld long double
#define ui uint64_t
#define cont(set, element) ((set).find(element) != (set).end())
 
/********* DEBUG *********/
 
template <typename T>
void outvec(const vector<T>& Z){
    for (const T& x : Z)
    cout << x << ' ';
    cout << "\n";
}
void printVariable(const any& var) {
    if (!var.has_value()) {
        cout << "null";
        return;
    }

    if (var.type() == typeid(int)) {
        cout << any_cast<int>(var);
    } else if (var.type() == typeid(double)) {
        cout << any_cast<double>(var);
    } else if (var.type() == typeid(float)) {
        cout << any_cast<float>(var);
    } else if (var.type() == typeid(char)) {
        cout << any_cast<char>(var);
    } else if (var.type() == typeid(bool)) {
        cout << (any_cast<bool>(var) ? "true" : "false");
    } else if (var.type() == typeid(string)) {
        cout << any_cast<string>(var);
    } else if (var.type() == typeid(const char*)) {
        cout << any_cast<const char*>(var);
    } else if (var.type() == typeid(long long)) {
        cout << any_cast<long long>(var);
    } else {
        cout << "[unknown type]";
    }
}

template<typename... Args>
void outval(Args... args) {
    vector<any> variables = {args...};
    
    for (size_t i = 0; i < variables.size(); ++i) {
        printVariable(variables[i]);
        if (i != variables.size() - 1) {
            cout << " ";
        }
    }
    cout << "\n";
}

#define nl "\n"
#define sp << " " <<

/********* DEBUG *********/

const ll MOD = 1000000007;
const ll inf = 1e18;
const ll mxN = 2000005;

vector<int> heights(mxN);
int n;

// offline queries yeehaw

/*
    Need 1: check if node x reachable from node y
    Solution: range max query them

    Need 2: min steps to reach node y
    Solution: create tree like structure, subtract depths

    Need 3: handle range queries
    Solution: idk
*/


vector<ll> pref(mxN), suff(mxN);

void init(int N, vector<int> H) {
    n=N;
    heights.resize(n);
    pref.resize(n);
    suff.resize(n);

    for (int i = 0; i < n; i++)
        heights[i] = H[i];
    
    // [height, idx]
    stack<pair<ll, ll>> st;
    for (int i = 0; i < n; i++){
        while (st.size() && st.top().first < heights[i])
            st.pop();
        
        if (st.empty())
            pref[i] = -1;
        else
            pref[i] = st.top().second;

        st.push({heights[i], i});
    }

    while(st.size())
        st.pop();

    for (int i = n-1; i >= 0; i--){
        while (st.size() && st.top().first < heights[i])
            st.pop();

        if (st.empty())
            suff[i] = -1;
        else
            suff[i] = st.top().second;
        
        st.push({heights[i], i});
    }
    // outvec(pref);
    // outvec(suff);
}   


// subtask 5
int minimum_jumps(int A, int B, int C, int D) {
    ll peak = 0;
    for (int i = C; i <= D; i++){
        peak = max(peak, (ll)heights[i]);
    }

    vector<int> vis(n, -1);

    ll ans = INT_MAX;
    for (int i = B; i >= A; i--){
        ll ptr = i, moves = 0;
        bool reach = false;

        while (true){
            //outval("ptr:",ptr);
            if (vis[ptr] != -1 && moves > vis[ptr])
                break;
            vis[ptr] = moves;

            bool flag = false;
            ll hl = pref[ptr] == -1 ? -1 : heights[pref[ptr]];
            ll hr = suff[ptr] == -1 ? -1 : heights[suff[ptr]];

            if (hl > peak)
                hl = -1;
            
            if (hr > peak)
                hr = -1;

            //outval("hl,hr:",hl,hr);

            if (hr != -1 && (hr > hl || (suff[ptr] >= C && suff[ptr] <= D)))
                ptr = suff[ptr], moves++, flag = true;
            else if (hl != -1 && hl > hr)
                ptr = pref[ptr], moves++, flag = true;
            
            if (ptr >= C && ptr <= D){
                reach = true;
                break;
            } 

            if (!flag)
                break;
        }

        if (reach)
            ans = min(ans, moves);
    }

    return ans == INT_MAX ? -1 : ans;
}

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