Submission #1184370

#	Time	Username	Problem	Language	Result	Execution time	Memory
1184370		thangdz2k7	Rainforest Jumps (APIO21_jumps)	C++20	33 / 100	4083 ms	5412 KiB

jumps

#ifdef EVAL

#include "jumps.h"

#endif

#include <bits/stdc++.h>

using namespace std;

const int MAX = 2e5 + 5;

int n, h[MAX], l[MAX], r[MAX];

void init(int N, vector <int> H){
    n = N;
    for (int i = 0; i < n; ++ i)
        h[i + 1] = H[i];

    r[0] = n + 1;
    vector <int> stk;
    for (int i = 1; i <= n; ++ i){
        while (stk.size() && h[i] > h[stk.back()])
            stk.pop_back();

        l[i] = stk.size() ? stk.back() : 0;
        stk.push_back(i);
    }

    stk.clear();
    for (int i = n; i >= 1; -- i){
        while (stk.size() && h[i] > h[stk.back()])
            stk.pop_back();

        r[i] = stk.size() ? stk.back() : n + 1;
        stk.push_back(i);
    }
}

int minimum_jumps(int a, int b, int c, int d){
    a ++, b ++, c ++, d ++;
    int st = 0;
    for (int i = b; i >= a; -- i) if (r[i] <= d) {
        if (!st || h[i] > h[st])
            st = i;
    }
    else break;

    int ans = 0;
    while (st < c && r[st] <= d){
        int i = l[st], j = r[st];
        if (h[i] < h[j]) swap(i, j);
        ans ++;
        if (c <= i && i <= d) return ans;
        if (c <= j && j <= d) return ans;
        if (r[i] <= d) st = i;
        else st = j;
    }

    if (st >= c) return ans;
    return -1;
}

/*
7 3
3 2 1 6 4 5 7
4 4 6 6
1 3 5 6
0 1 2 2
*/

• 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