Submission #1096406

#	Time	Username	Problem	Language	Result	Execution time	Memory
1096406		JuanJL	Mag (COCI16_mag)	C++17	0 / 120	611 ms	262144 KiB

mag

#include <bits/stdc++.h>
 
using namespace std;
 
#define pb push_back
#define forn(i,a,b) for(int i = a; i < b; i++)
#define mset(a,v) memset(a,v,sizeof(a))
 
typedef long long ll;
 
const int MAXN = 1000000+5;
 
struct fract{
	__int128 num; 
	__int128 den;
	fract(__int128 num = 1, __int128 den = 1) : num(num) , den(den) {}
};
 
bool operator<(const fract &a, const fract &b) {
	__int128 mcm = (a.den*b.den)/__gcd(a.den,b.den);	
	return (a.num*(mcm/a.den)) < (b.num*(mcm/b.den));
}

fract reduc(fract a){
	ll gcd;
	do{
		gcd=__gcd(a.num,a.den);
		a.num/=gcd;
		a.den/=gcd;
	}while(gcd!=1);
	return a;
}
 
ll n;
vector<ll> adj[MAXN];
ll parent[MAXN];
ll magic[MAXN];
fract down[MAXN];
fract def[MAXN];
 
void downcalc(ll nd){
	down[nd].num=magic[nd];
	down[nd].den=1;
	for(auto i:adj[nd]){
		downcalc(i);
		down[nd] = min(down[nd],fract(down[nd].num*down[i].num,down[nd].den+down[i].den));
	}
}
 
void calc(ll nd){
	def[nd] = down[nd];
	if(parent[nd] != -1){
		def[nd] = min(def[nd],fract(magic[parent[nd]]*def[nd].num,def[nd].den+1));
		for(auto i:adj[parent[nd]]){
			if(i==nd) continue;
			def[nd] = min( def[nd] , fract(def[nd].num*magic[parent[nd]]*down[i].num, def[nd].den+down[i].den+1));
		}
	}
	for(auto i:adj[nd]) calc(i);
}
 
int main(){
	mset(parent,-1);
	cin>>n;
	ll a,b;
	forn(i,0,n-1){
		cin>>a>>b; a--; b--;
		adj[a].pb(b);
		parent[b]=a;
	}
	forn(i,0,n) cin>>magic[i];
	
	ll root = 0;
	forn(i,0,n) if(parent[i] == -1) root = i;
	
	downcalc(root);
	
	/*fract res=down[root];
	forn(i,0,n){ res=min(res,down[i]);}
	cout<<to_string((ll)res.num)<<"/"<<to_string((ll)res.den)<<'\n';*/
	
	calc(root);
	
	fract res=def[root];
	forn(i,0,n){ res=min(res,def[i]);}
	cout<<to_string((ll)res.num)<<"/"<<to_string((ll)res.den)<<'\n';
	
	return 0;
}

• Subtask 1: 0 / 12
• Subtask 2: 0 / 12
• Subtask 3: 0 / 12
• Subtask 4: 0 / 12
• Subtask 5: 0 / 12
• Subtask 6: 0 / 12
• Subtask 7: 0 / 12
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• Subtask 10: 0 / 12