Submission #1071188

#	Time	Username	Problem	Language	Result	Execution time	Memory
1071188		stdfloat	Rainforest Jumps (APIO21_jumps)	C++17	4 / 100	1059 ms	74052 KiB

jumps

#include <bits/stdc++.h>
#include "jumps.h"
// #include "stub.cpp"
using namespace std;

const int lg = 20;

vector<int> h;

vector<vector<int>> sp, spl, spr;

void init(int n, vector<int> H) {
    h = H;

    stack<int> s;
    spl.assign(n, vector<int>(lg, -1));
    for (int i = 0; i < n; i++) {
        while (!s.empty() && h[s.top()] < h[i]) s.pop();

        spl[i][0] = (s.empty() ? -1 : s.top());
        s.push(i);
    }

    while (!s.empty()) s.pop();
    
    sp = spr = spl;
    for (int i = n - 1; i >= 0; i--) {
        while (!s.empty() && h[i] > h[s.top()]) s.pop();

        if (s.empty()) sp[i][0] = spl[i][0];
        else {
            spr[i][0] = s.top();
            sp[i][0] = (spl[i][0] == -1 || h[spl[i][0]] < h[spr[i][0]] ? spr[i][0] : spl[i][0]);
        }
    
        s.push(i);
    }

    for (int i = 1; i < lg; i++) {
        for (int j = 0; j < n; j++) {
            if (sp[j][i - 1] != -1) sp[j][i] = sp[sp[j][i - 1]][i - 1];
            if (spl[j][i - 1] != -1) spl[j][i] = spl[spl[j][i - 1]][i - 1];
            if (spr[j][i - 1] != -1) spr[j][i] = spr[spr[j][i - 1]][i - 1];
        }
    }
}

int minimum_jumps(int a, int b, int c, int d) {
    for (int i = lg - 1; i >= 0; i--) {
        if (spl[b][i] != -1 && h[spl[b][i]] < h[c]) b = spl[b][i];
    }
    
    int cnt = 0;
    for (int i = lg - 1; i >= 0; i--) {
        if (sp[b][i] != -1 && h[sp[b][i]] < h[c]) {
            cnt += (1 << i);
            b = sp[b][i];
        }
    }

    for (int i = lg - 1; i >= 0; i--) {
        if (spr[b][i] != -1 && h[spr[b][i]] < h[c]) {
            cnt += (1 << i);
            b = spr[b][i];
        }
    }

    return (spr[b][0] == c ? cnt + 1 : -1);
}

• 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