Submission #566839

#	Time	Username	Problem	Language	Result	Execution time	Memory
566839		amunduzbaev	Rainforest Jumps (APIO21_jumps)	C++17	0 / 100	1 ms	208 KiB

jumps

#include "jumps.h"

#ifndef EVAL
#include "stub.cpp"
#endif

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

const int B = 205;
const int N = 2e5 + 5;
int mx[N][20], mn[N][20], h[N];
int lx[N], rx[N];

void init(int n, vector<int> H){
	for(int i=0;i<n;i++){
		h[i] = H[i];
	}
	vector<int> ss;
	for(int i=0;i<n;i++){
		while(!ss.empty() && h[ss.back()] < h[i]) ss.pop_back();
		if(!ss.empty()) lx[i] = ss.back();
		else lx[i] = n;
		ss.push_back(i);
	} ss.clear();
	for(int i=n-1;~i;i--){
		while(!ss.empty() && h[ss.back()] < h[i]) ss.pop_back();
		if(!ss.empty()) rx[i] = ss.back();
		else rx[i] = n;
		ss.push_back(i);
	} ss.clear();
	h[n] = N;
	
	for(int i=0;i<n;i++){
		if(h[lx[i]] < h[rx[i]]){
			swap(lx[i], rx[i]);
		} 
		mn[i][0] = rx[i];
		mx[i][0] = lx[i];
	}
	mn[n][0] = mx[n][0] = n;
	for(int i=0;i<n;i++) cout<<mn[i][0]<<" ";
	cout<<"\n";
	for(int i=0;i<n;i++) cout<<mx[i][0]<<" ";
	cout<<"\n";
	
	for(int j=1;j<20;j++){
		for(int i=0;i<=n;i++){
			mn[i][j] = mn[mn[i][j-1]][j-1];
			mx[i][j] = mx[mx[i][j-1]][j-1];
		}
	}
}

int minimum_jumps(int a, int b, int c, int d) {
	int res = 0;
	for(int i=19;~i;i--){
		if(h[mx[a][i]] <= h[c]){
			//~ cout<<mx[a][i]<<" "<<h[mx[a][i]]<<" "<<h[c]<<"\n";
			//~ cout<<i<<"\n";
			a = mx[a][i], res += (1 << i);
		}
	}
	for(int i=19;~i;i--){
		if(h[mn[a][i]] <= h[c]){
			//~ cout<<mx[a][i]<<" "<<h[mx[a][i]]<<" "<<h[c]<<"\n";
			a = mn[a][i], res += (1 << i);
		}
	}
	if(a != c) return -1;
	return res;
}

/*

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