重构树解法,为什么数组开到2*N会TLE,开到4*N就AC了?????
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重构树解法,为什么数组开到2*N会TLE,开到4*N就AC了?????
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wanghai673楼主2021/10/5 22:44

重构后不是最多2*n-1个节点吗????

#define IOS ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#include<bits/stdc++.h>
using namespace std;
const int N = 200010,M = 500010,inf = 2e9 + 10;
typedef pair<int,int> P;
vector<P> v[N];
vector<int> mp[N*2];
int dis[N],n,fa[N*2],sz,f[N*2][22],h[N*2],min_dis[N*2];
struct edge{
	int a,b,w;
}e[M];
priority_queue<P,vector<P>,greater<P> >Q;
void get_dis(){
	for(int i = 1;i<=n;++i)dis[i] = inf;
	dis[1] = 0;
	Q.push(P(0,1));
	while(!Q.empty()){
		auto t = Q.top();
		Q.pop();
		int d = t.first, s = t.second;
		if(dis[s]<d)continue;
		for(int i = 0;i<v[s].size();++i){
			int to = v[s][i].first,w = v[s][i].second;
			if(dis[to]>d+w){
				dis[to] = d+w;
				Q.push(P(dis[to],to));
			}
		}
	}
}
int find(int n){return fa[n]==n?n:fa[n]=find(fa[n]);}
bool cmp(edge a,edge b){
	return a.w>b.w;
}
void dfs(int s){
	if(s<=n){
		min_dis[s] = dis[s];
		return ;
	}
	for(int i = 0;i<mp[s].size();++i){
		dfs(mp[s][i]);
		min_dis[s] = min(min_dis[s],min_dis[mp[s][i]]);
	}
}
int get_node(int v,int p){
	for(int i = 21;i>=0;--i){
		if(h[f[v][i]]>p){
			v = f[v][i];
		}
	}
	return v;
}
int main(){
	//IOS;
	//freopen("a.txt","r",stdin);
	//freopen("ans.txt","w",stdout);
	int T;
	cin>>T;
	while(T--){
		while(!Q.empty())Q.pop(); 
		for(int i = 0;i<N;++i){
			v[i].clear();
			mp[i].clear();
		}
		int m;
		cin>>n>>m;
		sz = n;
		for(int i = 1;i<=m;++i){
			int x,y,l,a;
			cin>>x>>y>>l>>a;
			v[x].push_back(P(y,l));
			v[y].push_back(P(x,l));
			e[i].a = x;
			e[i].b = y;
			e[i].w = a;
		}
		get_dis();
		sort(e+1,e+1+m,cmp);
		for(int i = 0;i<2*N;++i)fa[i] = i,min_dis[i] = inf;
		for(int i = 1;i<=m;++i){
			int ta = find(e[i].a),tb = find(e[i].b);
			if(ta!=tb){
				fa[ta] = ++sz;
				fa[tb] = sz;
				f[ta][0] = sz;
				f[tb][0] = sz;
				h[sz] = e[i].w;
				mp[sz].push_back(ta);
				mp[sz].push_back(tb);
			}
		}
		dfs(sz);
		for(int j = 1;j<22;++j){
			for(int i = 1;i<=sz;++i)f[i][j] = f[f[i][j-1]][j-1];
		}
		int q,k,s,lastans = 0;
		cin>>q>>k>>s;
		
		for(int i = 1;i<=q;++i){
			int v,p;
			cin>>v>>p;
			v = (v+k*lastans-1)%n+1;
			p = (p+k*lastans)%(s+1);
			v = get_node(v,p);
			lastans = min_dis[v]; 
			cout<<min_dis[v]<<endl; 
		}	
	}
	
	return 0;
} 

好奇???

2021/10/5 22:44
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