Submission #855127

#	Time	Username	Problem	Language	Result	Execution time	Memory
855127		PoPularPlusPlus	Rainforest Jumps (APIO21_jumps)	C++17	100 / 100	976 ms	86608 KiB

jumps

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

#define ll long long
#define pb(x) push_back(x)
#define mp(x,y) make_pair(x,y)
#define all(x) x.begin(),x.end()
#define vf first 
#define vs second
const int mod = 998244353;

const int N = 200001 , B = 20;

int n;
int arr[N] , left_edge[N] , right_edge[N];
vector<int> gl[N],gr[N],gmx[N];
int upl[N][B], upr[N][B], upmx[N][B];

void dfsl(int node , int par){
	upl[node][0] = par;
	for(int i = 1; i < B; i++){
		upl[node][i] = upl[upl[node][i-1]][i-1];
	}
	for(int i : gl[node]){
		dfsl(i,node);
	}
}

void dfsr(int node , int par){
	upr[node][0] = par;
	for(int i = 1; i < B; i++){
		upr[node][i] = upr[upr[node][i-1]][i-1];
	}
	for(int i : gr[node]){
		dfsr(i,node);
	}
}

void dfsmx(int node , int par){
	upmx[node][0] = par;
	for(int i = 1	; i < B; i++){
		upmx[node][i] = upmx[upmx[node][i-1]][i-1];
	}
	for(int i : gmx[node]){
		dfsmx(i,node);
	}
}

void init(int n1 , vector<int> h){
	n = n1;
	for(int i = 0; i < n; i++)
		arr[i] = h[i];
	stack<pair<int,int>> s;
	s.push(mp(1e9+10,n));
	memset(left_edge,-1,sizeof left_edge);
	memset(right_edge,-1,sizeof right_edge);
	for(int i = 0; i < n; i++){
		while(s.size() && s.top().vf < arr[i]){
			s.pop();
		}
		if(s.size())
			left_edge[i] = s.top().vs;
		s.push(mp(arr[i],i));
	}
	while(s.size())s.pop();
	s.push(mp(1e9+10,n));
	for(int i = n - 1; i >= 0; i--){
		while(s.size() && s.top().vf < arr[i]){
			s.pop();
		}
		if(s.size())
			right_edge[i] = s.top().vs;
		s.push(mp(arr[i],i));
	}
	for(int i = 0; i < n; i++){
		gl[left_edge[i]].pb(i);
		gr[right_edge[i]].pb(i);
		if(left_edge[i] != n || right_edge[i] != n){
			if(left_edge[i] == n)gmx[right_edge[i]].pb(i);
			else if(right_edge[i] == n)gmx[left_edge[i]].pb(i);
			else if(arr[left_edge[i]] > arr[right_edge[i]])gmx[left_edge[i]].pb(i);
			else gmx[right_edge[i]].pb(i);
		}
	}
	dfsl(n,n);
	dfsr(n,n);
	int mx_pos = -1 , mx = -1;
	for(int i = 0; i < n; i++){
		if(mx < arr[i]){
			mx = arr[i];
			mx_pos = i;
		}
	}
	dfsmx(mx_pos,mx_pos);
}

int binary_liftingl(int start , int stop){
	for(int i = B-1; i >= 0; i--){
		if(upl[start][i]!=n && upl[start][i] > stop){
			start = upl[start][i];
		}
	}
	return start;
}

int binary_liftingr(int start , int stop){
	for(int i = B-1; i >= 0; i--){
		if(upr[start][i]!=n && upr[start][i] < stop){
			start = upr[start][i];
		}
	}
	return start;
}


int final_bl_l(int start , int stop , int mx , int end , int s){
	int ans = 0;
	for(int i = B-1; i >= 0; i--){
		if(arr[upmx[start][i]] < stop){
			ans += (1 << i);
			start = upmx[start][i];
		}
	}
	if(arr[start] == stop)return ans;
	int x = start;
	int res = 0;
	for(int i = B-1; i >= 0; i--){
		if(upl[x][i]!=n && arr[upl[x][i]] < stop){
			res += (1 << i);
			x = upl[x][i];
		}
	}
	res++;
	int res1 = N;
	int node = upmx[start][0];
	if(node != n && node <= end && node >= s)res1 = 1;
	else res1 = 2;
	if(arr[node] < mx){
		ans += min(res , res1);
	}
	else ans += res;
	return ans;
}

int final_bl_r(int start , int stop , int mx , int end , int s){
	int ans = 0;
	for(int i = B-1; i >= 0; i--){
		if(arr[upmx[start][i]] < stop){
			ans += (1 << i);
			start = upmx[start][i];
		}
	}
	if(arr[start] == stop)return ans;
	int x = start;
	int res = 0;
	for(int i = B-1; i >= 0; i--){
		if(upr[x][i]!=n && arr[upr[x][i]] < stop){
			res += (1 << i);
			x = upr[x][i];
		}
	}
	res++;
	int res1 = N;
	int node = upmx[start][0];
	if(node != n && node >= end && node <= s)res1 = 1;
	else res1 = 2;
	if(arr[node] < mx){
		ans += min(res , res1);
	}
	else ans += res;
	return ans;
}

int bl_l(int start , int end , int mx){
	for(int i = B-1; i >= 0; i--){
		if(upr[start][i] != n && upr[start][i] <= end && arr[upr[start][i]] < mx){
			start = upr[start][i];
		}
	}
	return start;
}

int bl_r(int start , int end , int mx){
	for(int i = B-1; i >= 0; i--){
		if(upl[start][i] != n && upl[start][i] >= end && arr[upl[start][i]] < mx){
			start = upl[start][i];
		}
	}
	return start;
}


int type_left(int a , int b , int c , int d){
	int pos = upl[binary_liftingl(a,d)][0];
	if(pos < c || pos == n)return -1;
	int mx_pos = binary_liftingl(pos , c-1);
	int mx = arr[mx_pos];
	return final_bl_l(bl_l(a,b,arr[pos]),arr[pos],mx,b,a);
}

int type_right(int a , int b , int c , int d){
	int pos = upr[binary_liftingr(b,c)][0];
	if(pos > d || pos == n)return -1;
	int mx_pos = binary_liftingr(pos , d+1);
	int mx = arr[mx_pos];
	return final_bl_r(bl_r(b,a,arr[pos]),arr[pos],mx,a,b);
}

int minimum_jumps(int a,  int b, int c, int d){
	if(!(c > b || a > d))return 0;
	if(a > c)return type_left(a,b,c,d);
	else return type_right(a,b,c,d);
}

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