Submission #972326

#	Time	Username	Problem	Language	Result	Execution time	Memory
972326		Syrius	Rainforest Jumps (APIO21_jumps)	C++14	0 / 100	27 ms	58704 KiB

jumps

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

// #define int long long
#define ll long long
#define ff first
#define ss second
#define pint pair < int , int >
#define fast ios_base::sync_with_stdio(NULL); cin.tie(NULL)
typedef vector < int > vint;

const int inf = 1e9 + 9;
const int mxn = 2e5 + 2;
const int mod = 1e9 + 7;

int n;
int h[mxn] , le[mxn] , ri[mxn];
int spx[19][mxn] , spn[19][mxn];

void init(int N , vint H) {
	n = N;
	vint v;
	for (int i = 0; i < n; i++) {
		h[i] = H[i];
	}

	for (int i = 0; i < n; i++) {
		if (!v.empty()) {
			while (v.back() < h[i]) {
				ri[v.back()] = h[i];
				v.pop_back();
			}
		}
		if (!v.empty()) le[i] = v.back();
		v.push_back(h[i]);
	}

	for (int i = 0; i < n; i++) {
		spx[0][h[i]] = max(le[h[i]] , ri[h[i]]);
		spn[0][h[i]] = min(le[h[i]] , ri[h[i]]);
		if (spn[0][h[i]] == 0) spn[0][h[i]] = spx[0][h[i]];
	}

	for (int j = 1; j < 19; j++) {
		for (int i = 0; i < n; i++) {
			spx[j][h[i]] = spx[j-1][spx[j-1][h[i]]];
			spn[j][h[i]] = spn[j-1][spn[j-1][h[i]]];
		}
	}
}

int minimum_jumps(int a , int b , int c , int d) {
	if (h[a] > h[d]) return -1;
	int dis = 0;
	for (int i = 18; i >= 0; i--) {
		if (spx[i][h[a]] > h[d]) continue;
		if (spx[i][h[a]] == h[d]) return (1 << i);
		return (1 << i) + minimum_jumps(spx[i][h[a]] , b , c , d);
	}

	for (int i = 18; i >= 0; i--) {
		if (spn[i][h[a]] > h[d]) continue;
		if (spn[i][h[a]] == h[d]) return (1 << i);
		return (1 << i) + minimum_jumps(spn[i][h[a]] , b , c , d);
	}

	return -1;
}

Compilation message (stderr)

jumps.cpp: In function 'int minimum_jumps(int, int, int, int)':
jumps.cpp:55:6: warning: unused variable 'dis' [-Wunused-variable]
   55 |  int dis = 0;
      |      ^~~

• Subtask 1: 0 / 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