Submission #1215051

#	Time	Username	Problem	Language	Result	Execution time	Memory
1215051		lrnnz	Rainforest Jumps (APIO21_jumps)	C++20	100 / 100	566 ms	155596 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 sp << " " <<

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

const ll MOD = 1e9+7;
const ll MOD2 = 998244353;
const ll inf = 1e18;
const ll mxN = 2000005;

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

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

const ll LOGN = 22;
ll jumpR[mxN][LOGN], jumpL[mxN][LOGN];
ll realJump[mxN][LOGN];

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);

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

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

    for (int i = 0; i < LOGN; i++){
        for (int j = 0; j < n; j++){
            if (i == 0){
                if (suff[j] == -1 && pref[j] == -1)
                    realJump[j][i] = -1;
                
                if (suff[j] == -1)
                    realJump[j][i] = pref[j];
                else if (pref[j] == -1)
                    realJump[j][i] = suff[j];
                else
                    realJump[j][i] = heights[suff[j]] > heights[pref[j]] ? suff[j] : pref[j];
            }
            else if (realJump[j][i-1] != -1)
                realJump[j][i] = realJump[ realJump[j][i-1] ][ i-1 ];
            else
                realJump[j][i] = -1;
        }
    }
}   

// subtask 5
int minimum_jumps(int A, int B, int C, int D) {
    ll curr = B, moves = 0;

    if (jumpR[B][0] != -1 && jumpR[B][0] <= D && jumpR[B][0] >= C)
        return 1;

    if (B + 1 == C)
        return -1;

    // find mPeak
    ll mPeak = B+1;
    for (int i = LOGN-1; i >= 0; i--){
        if (jumpR[mPeak][i] == -1)
            continue;

        if (jumpR[mPeak][i] < C)
            mPeak = jumpR[mPeak][i];
    }

    // jumpR from mPeak is invalid
    if (jumpR[mPeak][0] == -1 || jumpR[mPeak][0] > D)
        return -1;

    // useless mPeak
    if (heights[mPeak] < heights[B])
        return -1;

    // find lPeak, height[lPeak] < height[mPeak]
    for (int i = LOGN-1; i >= 0; i--){
        if (jumpL[curr][i] == -1)
            continue;
            
        if (jumpL[curr][i] >= A && heights[jumpL[curr][i]] < heights[mPeak])
            curr = jumpL[curr][i];
    }

    // try to move left, as left is def lower than height[mPeak]
    // only if left is within [A, B], if not it'll be handled by logic later
    ll left = jumpL[curr][0];
    if (left != -1 && left >= A && jumpR[left][0] >= C && jumpR[left][0] <= D)
        return 1;

    for (int i = LOGN-1; i >= 0; i--){
        if (realJump[curr][i] == -1)
            continue;

        if (heights[realJump[curr][i]] < heights[mPeak])
            curr = realJump[curr][i], moves += (1 << i);
    }

    // if we land in mPeak
    if (curr == mPeak)
        return moves + 1;

    // now we try to jump left and right
    left = jumpL[curr][0];
    if (left != -1 && jumpR[left][0] >= C && jumpR[left][0] <= D)
        return moves + 2;


    // just jump right directly to mPeak. we never go left now
    for (int i = LOGN-1; i >= 0; i--){
        if (curr == mPeak)
            break;
        
        if (jumpR[curr][i] == -1)
            continue;

        if (jumpR[curr][i] <= mPeak)
            curr = jumpR[curr][i], moves += (1 << i);
    }

    return moves + 1;
}

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