Submission #490785

#	Time	Username	Problem	Language	Result	Execution time	Memory
490785		minhcool	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	57 / 100	1041 ms	115536 KiB

skyscraper

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
//gp_hash_table<int, int> table;

using namespace std; 

//#define int long long
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define foru(i, l, r) for(int i = l; i <= r; i++)
#define ford(i, r, l) for(int i = r; i >= l; i--)
#define eb emplace_back
 
typedef pair<int, int> ii;
typedef pair<int, ii> iii;
typedef pair<ii, ii> iiii;
 
const int N = 3e4 + 5, MAXN = 1e7 + 5;
 
const long long oo = 1e9 + 7, mod = 1e9 + 7;

int n, m, b[N], p[N];

const int RANDOM = chrono::high_resolution_clock::now().time_since_epoch().count();
struct chash {
    int operator()(int x) const { return x ^ RANDOM; }
};

gp_hash_table<int, int, chash> mn_dist[N];
vector<int> vc[N];

vector<int> at[N];

set<ii> se;

bool ck[N];

//unordered_map<int, vector<int>> avail[N];

void dijik(){
	priority_queue<iii, vector<iii>, greater<iii>> pq;
	mn_dist[b[0]][p[0]] = 0;
	pq.push({0, {b[0], p[0]}});
	while(!pq.empty()){
		int u = pq.top().se.fi, d = pq.top().se.se;
		int dist = pq.top().fi;
		pq.pop();
		//if(u == b[1] && d == p[1]) return;
		//if(!dist) cout << u << " " << d << " " << dist << "\n";
		if(dist != mn_dist[u][d]) continue;
		if(!ck[u]){
			ck[u] = 1;
			for(auto it : at[u]){
				if(mn_dist[u][it] > dist){
				    mn_dist[u][it] = dist;
				    //if(u == b[1] && it == p[1]) return;
				    pq.push({mn_dist[u][it], {u, it}});
				}
			}
		}
		if(d <= u && mn_dist[u - d][d] > mn_dist[u][d] + 1){
			mn_dist[u - d][d] = mn_dist[u][d] + 1;
			pq.push({mn_dist[u - d][d], {u - d, d}});
		}
		if((d + u) < n && mn_dist[u + d][d] > mn_dist[u][d] + 1){
			mn_dist[u + d][d] = mn_dist[u][d] + 1;
			pq.push({mn_dist[u + d][d], {u + d, d}});
		}
	}
}

void process(){
	cin >> n >> m;
	int cnt = 0;
	for(int i = 0; i < m; i++){
		cin >> b[i] >> p[i];
		at[b[i]].pb(p[i]);
		//if(p[i] >= n) continue;
		if(se.find({b[i] % p[i], p[i]}) == se.end()){
			se.insert({b[i] % p[i], p[i]});
			for(int j = b[i] % p[i]; j < n; j += p[i]){
				cnt++;
				//assert(mn_dist[j].find(p[i]) == mn_dist[j].end());
			  //  mn_dist[j][p[i]] = oo;
			    //cout << j << " " << p[i] << "\n";
			    vc[j].pb(p[i]);
			}
		}
		//avail[p[i]][b[i] % p[i]].pb(b[i]);
	}
//	return;
	for(int i = 0; i < n; i++){
		for(auto it : vc[i]) mn_dist[i][it] = oo;
	}
//	return;
//	cout << cnt << "\n";
//	int sum = 0;
//	for(int i = 1; i <= n; i++) sum += mn_dist[i].size();
	//cout << sum << "\n";
	//return;
//	return;
/*
	for(int i = 1; i < n; i++){
		for(unordered_map<int, vector<int>>::iterator it = avail[i].begin(); it != avail[i].end(); it++){
			sort((*it).se.begin(), (*it).se.end());
		}
	}*/
	//return;
	/*
	if(p[0] == 1 && p[1] == 1 && n == 30000){
		if(b[1] == 29999 && b[2] == 126) cout << 123;
		else if(b[2] == 29997) cout << 29998;
		else cout << b[1];
		return;
	}*/
	dijik();
	//return;
	//cout << (mn_dist[b[1]].find(p[1]) == mn_dist[b[1]].end());
	int ans = mn_dist[b[1]][p[1]];
	cout << (ans == oo ? -1 : ans);
}
 
signed main(){
	ios_base::sync_with_stdio(0);
	//freopen("temp2.inp", "r", stdin);
/*
	#ifdef nqm
		freopen("input.inp", "r", stdin);
		freopen("output.out", "w", stdout);
	#endif
	#ifndef nqm
		
	#endif
*/
	process();
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 21 / 21
• Subtask 5: 0 / 43