Submission #680176

#	Time	Username	Problem	Language	Result	Execution time	Memory
680176		minhcool	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	57 / 100	1091 ms	202168 KiB

skyscraper

#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#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;
	deque<ii> pq;
	mn_dist[b[0]][p[0]] = 0;
	pq.push_front({b[0], p[0]});
	while(!pq.empty()){
		int u = pq.front().fi, d = pq.front().se;
		int dist = mn_dist[u][d];
		pq.pop_front();
		//cout << u << " " << d << " " << mn_dist[u][d] << "\n";
		if(!ck[u]){
			ck[u] = 1;
			for(auto it : at[u]){
				if(mn_dist[u][it] > dist){
				    mn_dist[u][it] = dist;
				    pq.push_front({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_back({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_back({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(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++;
			    vc[j].pb(p[i]);
			}
		}
	}
	for(int i = 0; i < n; i++){
		for(auto it : vc[i]) mn_dist[i][it] = oo;
	}
	dijik();
	int ans = mn_dist[b[1]][p[1]];
	cout << (ans == oo ? -1 : ans);
}
 
signed main(){
	ios_base::sync_with_stdio(0);
	process();
}

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