Submission #1304757

#	Time	Username	Problem	Language	Result	Execution time	Memory
1304757		vtnoo	Swapping Cities (APIO20_swap)	C++20	7 / 100	157 ms	39316 KiB

swap

#include "swap.h"
#include <bits/stdc++.h>
#define pb push_back
#define fst first
#define snd second
#define fore(i,a,b) for(int i=a,pao=b;i<pao;++i)
#define SZ(x) ((int)x.size())
#define ALL(x) x.begin(),x.end()
#define mset(a,v) memset((a),(v),sizeof(a))
#define FIN ios::sync_with_stdio(0);cin.tie(0);cout.tie(0)
using namespace std;
typedef long long ll;
const int MAXN=3e5+5,LOG=20,INF=1e9+7;
int n,m;
int z[MAXN],r[MAXN],up[MAXN][LOG],par[MAXN],tam[MAXN],deg[MAXN],dep[MAXN],dp[MAXN];
vector<int>chi[MAXN];
bool info[MAXN];
struct Edge{
	int a,b,c;
	bool operator<(const Edge&o)const{
		return c<o.c;
	}
};
int find(int x){
	while(par[x]!=x)x=par[x];
	return x;
}
void dsu(int a,int b){
	if(tam[a]<tam[b])swap(a,b);
	tam[a]+=tam[b];
	par[b]=a;
}
void dfs(int u,int p,int d){
	dep[u]=d;
	for(auto v:chi[u]){
		if(v==p)continue;
		up[v][0]=u;
		dp[v]=min(dp[v],dp[u]);
		dfs(v,u,d+1);
	}
}
void init(int N, int M, std::vector<int> U, std::vector<int> V, std::vector<int> W) {
    n=N,m=M;
	vector<Edge>e;
	fore(i,0,m){
		e.pb({U[i],V[i],W[i]});
	}
	sort(ALL(e));
	int nxt=n;
	iota(r,r+n+m,0);
	iota(par,par+n,0);
	mset(tam,1);
	for(auto[a,b,c]:e){
		int ca=find(a),cb=find(b);
		deg[a]++;deg[b]++;
		z[nxt]=c;
		if(ca!=cb){
			chi[nxt].pb(r[ca]);
			chi[nxt].pb(r[cb]);
			dsu(a,b);
			info[nxt]=info[r[ca]]|info[r[cb]];
			r[ca]=r[cb]=nxt;
		}else{//tengo ciclo 
			chi[nxt].pb(r[ca]);
			info[nxt]=true;
			r[ca]=nxt;
		}
		if(deg[a]>=3||deg[b]>=3)info[nxt]=true;
		nxt++;
	}
	fore(i,0,nxt){
		dp[i]=INF;
		if(info[i])dp[i]=z[i];
	}
	dfs(nxt-1,nxt-1,0);
	fore(i,1,LOG){
		fore(j,0,nxt){
			up[j][i]=up[up[j][i-1]][i-1];
		}
	}
}
int jump(int a, int d){
	fore(i,0,LOG){
		if(d&(1<<i))a=up[a][i];
	}
	return a;
}
int LCA(int a,int b){
	if(dep[a]>dep[b])swap(a,b);
	b=jump(b,dep[b]-dep[a]);
	if(a==b)return a;
	for(int i=LOG-1;i>=0;i--){
		if(up[a][i]!=up[b][i]){
			a=up[a][i];
			b=up[b][i];
		}
	}
	return up[a][0];
}
int getMinimumFuelCapacity(int X, int Y) {
	int Z=LCA(X,Y);
	if(dp[Z]==INF)return -1;
	return dp[Z];
}

• Subtask 1: 0 / 6
• Subtask 2: 7 / 7
• Subtask 3: 0 / 17
• Subtask 4: 0 / 20
• Subtask 5: 0 / 23
• Subtask 6: 0 / 27