Submission #575542

#	Time	Username	Problem	Language	Result	Execution time	Memory
575542		Pietra	Pictionary (COCI18_pictionary)	C++14	0 / 140	258 ms	20716 KiB

pictionary

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

const int maxl = 22 ; 
const int maxn = 2e5 + 5 ; 

int n, m, q ;
int  tab[maxl][maxn], mx[maxl][maxn], nivel[maxn] ; 
int sz[maxn], pai[maxn] ; 

struct DSU{

	int find(int a){return (pai[a] == a ? a : pai[a] = find(pai[a])) ; }

	void join(int a, int b, int id){
		a = find(a), b = find(b) ; 
		if(sz[a] > sz[b]) swap(a, b) ;
		tab[0][a] = b ; mx[0][a] = id ;  nivel[a] = nivel[b] + 1 ; 
		sz[b] += sz[a] ; pai[a] = b ; 
	}

} dsu ; 

int lca(int a, int b){
	
	int ans = 0 ; 

	if(nivel[a] > nivel[b]) swap(a, b) ; 

	for(int i = maxl - 1 ; i >= 0 ; i--){
		if(tab[i][b] != -1 && nivel[tab[i][b]] >= nivel[a]){
			ans = max(ans, mx[i][b]) ;
			b = tab[i][b] ; 
		}
	}

	if(a == b) return ans ; 

	for(int i = maxl - 1 ; i >= 0 ; i--){
		if(tab[i][a] != -1 && tab[i][b] != -1 && tab[i][a] != tab[i][b]){
			ans = max({mx[i][a], ans, mx[i][b]}) ; 
			b = tab[i][b], a = tab[i][a] ; 
		}
	}

	return max({ans, mx[0][a], mx[0][b]}) ; 
	
}

int main(){

	cin >> n >> m >> q ; 

	for(int i = 1 ; i <= n ; i++) pai[i] = i, sz[i] = 1 ; 

	for(int i = 1 ; i < maxl ; i++){
		for(int j = 1 ; j <= n ; j++){
			tab[i][j] = -1 ; 
		}
	}

	for(int md = m ; md > 0 ; md--){
		for(int id = md + md ; id <= n ; id += md){
			if(dsu.find(md) == dsu.find(id)) continue ; 
			dsu.join(md, id, m - md + 1) ; 
		}
	}

	for(int i = 1 ; i < maxl ; i++){
		for(int j = 1 ; j <= n ; j++){
			if(tab[i-1][j] == -1) continue ; 
			mx[i][j] = max(mx[i-1][j], mx[i-1][tab[i-1][j]]) ; 
			tab[i][j] = tab[i-1][tab[i-1][j]] ; 
		}
	}

	for(int i = 1 ; i <= q ; i++){
		int a, b ; cin >> a >> b ; 
		cout << lca(a, b) << "\n" ; 
	}

}

• Subtask 1: 0 / 14
• Subtask 2: 0 / 14
• Subtask 3: 0 / 14
• Subtask 4: 0 / 14
• Subtask 5: 0 / 14
• Subtask 6: 0 / 14
• Subtask 7: 0 / 14
• Subtask 8: 0 / 14
• Subtask 9: 0 / 14
• Subtask 10: 0 / 14