Submission #744753

#	Time	Username	Problem	Language	Result	Execution time	Memory
744753		t6twotwo	Rainforest Jumps (APIO21_jumps)	C++17	12 / 100	4090 ms	14400 KiB

jumps

#include "jumps.h"
#include <bits/stdc++.h>
using namespace std;
int N;
vector<int> H;
bool subtask1;
vector<vector<int>> adj;
void init(int n, vector<int> h) {
    N = n, H = h;
    subtask1 = 1;
    for (int i = 0; i < N; i++) {
        H[i]--;
        if (i != H[i]) {
            subtask1 = 0;
        }
    }
    adj.resize(N);
    vector<int> stk;
    for (int i = N - 1; i >= 0; i--) {
        while (!stk.empty() && H[stk.back()] < H[i]) {
            stk.pop_back();
        }
        if (!stk.empty()) {
            adj[H[i]].push_back(H[stk.back()]);
        }
        stk.push_back(i);
    }
    stk.clear();
    for (int i = 0; i < N; i++) {
        while (!stk.empty() && H[stk.back()] < H[i]) {
            stk.pop_back();
        }
        if (!stk.empty()) {
            adj[H[i]].push_back(H[stk.back()]);
        }
        stk.push_back(i);
    }
}
int minimum_jumps(int A, int B, int C, int D) {
    if (subtask1) {
        return C - B;
    }
    int ans = N;
    for (int i = A; i <= B; i++) {
        for (int j = C; j <= D; j++) {
            int x = H[i], cnt = 0;
            while (x < H[j]) {
                int y = -1;
                for (int z : adj[x]) {
                    if (z <= H[j]) {
                        y = max(y, z);
                    }
                }
                if (y == -1) {
                    break;
                }
                cnt++;
                x = y;
            }
            if (x == H[j]) {
                ans = min(ans, cnt);
            }
        }
    }
    if (ans == N) {
        ans = -1;
    }
    return ans;
}

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