Submission #1084535

#	Time	Username	Problem	Language	Result	Execution time	Memory
1084535		peacebringer1667	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	205 ms	215724 KiB

skyscraper

#include<bits/stdc++.h>
#define ll long long
#define ldb long double
#define fi first
#define se second
#define sza(a) (int)a.size()
#define pir pair<int,int>
#define pirll pair<ll,ll>
using namespace std;
const int maxn = 3e4 + 5;

int B[maxn],P[maxn];
void input(int n){
    for (int i = 0 ; i < n ; i++)
      cin >> B[i] >> P[i];
}

namespace sub1{
	const int K = 2e3 + 5;
	bool check(int n){
		return (n <= K);
	}
	
	bool mark[K][K],vis[K];
	int dp[K];
	
	vector <vector<pir>> vec(100*K);
	vector <vector<int>> doge(K);

	void bfs(int n,int N){
		vec[0].push_back({B[0],P[0]});
	    
	    for (int len = 0 ; len < 100*N ; len++)
	      for (pir t : vec[len]){
	      	int Bi = t.fi,Pi = t.se;
			if (mark[Bi][Pi]) continue;
			
	      	mark[Bi][Pi] = 1;
	      	if (!vis[Bi])
			   dp[Bi] = len;
	      	
	      	if (Bi + Pi < N)
	      		vec[len + 1].push_back({Bi + Pi,Pi});
	      	if (Bi - Pi >= 0)
	      	    vec[len + 1].push_back({Bi - Pi,Pi});
	      	
	      	if (!vis[Bi])
	      	  for (int p : doge[Bi]){
	      	  	  if (Bi + p < N)
	      	  	    vec[len + 1].push_back({Bi + p,p});
	      	  	  if (Bi - p >= 0)
	      	  	    vec[len + 1].push_back({Bi - p,p});
				}
			
			vis[Bi] = 1;
		  }
	}
	
	int solve(int n,int N){
		//dp[i][k] : position i, jump k
		for (int i = 0 ; i < n ; i++)
		  doge[B[i]].push_back(P[i]);
		
		bfs(n,N);
		
		if (!vis[B[1]]) return -1;
		return dp[B[1]];
	}
}

namespace sub2{
	const int block = 150;
	
	bool vis[maxn];
	bool mark[maxn][block];
	int dp[maxn];
	
	vector <vector<pir>> vec(maxn*block + 10);
	vector <vector<int>> doge(maxn);
	
	void bfs(int n,int N){
		vec[0].push_back({B[0],P[0]});
		
		for (int len = 0 ; len < N * block ; len++)
		  for (pir t : vec[len]){
		  	int Bi = t.fi,Pi = t.se;
		  	
		  	if (Pi <= block && mark[Bi][Pi]) continue;
		  	if (Pi <= block) mark[Bi][Pi] = 1;
		  	
			if (!vis[Bi]) dp[Bi] = len;
		  	
		  	if (!vis[Bi])
		  	for (int p : doge[Bi])
		  	  if (p > block){
		  	     for (int x = Bi + p ; x < N ; x += p)
		  	       if (x < N && !vis[x])
		  	       	vec[len + (x - Bi)/p].push_back({x,p});
			     
			     for (int x = Bi - p ; x >= 0 ; x -= p)
			       if (x >= 0 && !vis[x])
			         vec[len + (Bi - x)/p].push_back({x,p});
			  }
			if (!vis[Bi])
	      	  for (int p : doge[Bi]) 
				 if (p <= block){
	      	  	  if (Bi + p < N)
	      	  	    vec[len + 1].push_back({Bi + p,p});
	      	  	  if (Bi - p >= 0)
	      	  	    vec[len + 1].push_back({Bi - p,p});
				}
		    
		    if (Pi <= block && Bi + Pi < N)
		      vec[len + 1].push_back({Bi + Pi,Pi});
		    
		    if (Pi <= block && Bi - Pi >= 0)
		      vec[len + 1].push_back({Bi - Pi,Pi});
			
			vis[Bi] = 1;
		  }
	}
	
	int solve(int n,int N){
		for (int i = 0 ; i < n ; i++)
		  doge[B[i]].push_back(P[i]);
		
		bfs(n,N);
		
		if (!vis[B[1]]) return -1;
		return dp[B[1]];
	}
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);cout.tie(0);
	
	int N,n;
	cin >> N >> n;
	input(n);
	
	if (sub1::check(N))
	  cout << sub1::solve(n,N);else
	
	cout << sub2::solve(n,N);
	
	return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 21 / 21
• Subtask 5: 43 / 43