Submission #601753

#	Time	Username	Problem	Language	Result	Execution time	Memory
601753		WongChun1234	Bridges (APIO19_bridges)	C++14	13 / 100	3065 ms	28276 KiB

bridges

#include<bits/stdc++.h>
using namespace std;
const int N=100050,B=500;
int n,m,q,t[N],a[N],b[N],u[N],v[N],w[N],par[N],sz[N],ans[N],rw[B+10][B+10],irw[N],rrl[B+10],pt,ret;
bool ch[N],vis[N];
vector<pair<int,int>> srt[N<<1];
vector<int> adj[N],del,dis;
unordered_map<int,int> dd;
int find(int u){
	return par[u]==u?u:par[u]=find(par[u]);
}
void onion(int u,int v){
	if (find(u)==find(v)) return;
	if (adj[find(u)].size()<adj[find(v)].size()) swap(u,v);
	//cout<<"onion"<<v<<" to "<<u<<"\n";
	for (int i:adj[find(v)]) adj[find(u)].push_back(i);
	sz[find(u)]+=sz[find(v)];
	sz[find(v)]=0;
	par[find(v)]=u;
}
void dfs(int nde,int lim,int curr){
	//cout<<curr<<": "<<nde<<"::"<<sz[nde]<<"\n";
	vis[nde]=1;
	del.push_back(nde);
	ret+=sz[nde];
	for (int i:adj[nde]){
		int des,cst;
		if (i<0) des=find(u[rrl[-i]]);
		else des=find(v[rrl[i]]);
		cst=rw[curr][abs(i)];
		//cout<<i<<":"<<cst<<"-->"<<des<<"\n";
		if (cst<lim||vis[des]) continue;
		dfs(des,lim,curr);
	}
}
int main(){
	cin.tie(0)->sync_with_stdio(0);
	cin>>n>>m;
	for (int i=1;i<=m;i++){
		cin>>u[i]>>v[i]>>w[i];
		dis.push_back(w[i]);
	}
	cin>>q;
	for (int i=1;i<=q;i++){
		cin>>t[i]>>a[i]>>b[i];
		dis.push_back(b[i]);
	}
	sort(dis.begin(),dis.end());
	dis.erase(unique(dis.begin(),dis.end()),dis.end());
	for (int i=0;i<dis.size();i++) dd[dis[i]]=i;
	for (int l=1;l<=q;l+=B){
		int r=min(q,l+B-1);
		for (int i=1;i<=m;i++) ch[i]=0,irw[i]=0;
		for (int i=0;i<dis.size();i++) srt[i].clear();
		pt=0;
		for (int i=l;i<=r;i++){
			if (t[i]==1){
				ch[a[i]]=1;
				if (!irw[a[i]]) irw[a[i]]=++pt;
				rrl[irw[a[i]]]=a[i];
				//cout<<pt<<":::"<<a[i]<<"\n";
			}
		}
		for (int i=1;i<=m;i++) if (!ch[i]) srt[dd[w[i]]].push_back({u[i],v[i]});
		for (int i=l;i<=r;i++) if (t[i]==2) srt[dd[b[i]]].push_back({INT_MAX,i});
		for (int i=1;i<=n;i++) par[i]=i,sz[i]=1;
		for (int i=1;i<=pt;i++) rw[0][i]=w[rrl[i]];
		for (int i=0;i<=r-l;i++){
			if (i) for (int j=1;j<=pt;j++) rw[i][j]=rw[i-1][j];
			if (t[l+i]==1) rw[i][irw[a[l+i]]]=b[l+i];
		}
		for (int i=1;i<=n;i++) adj[i].clear();
		for (int i=1;i<=m;i++) if (ch[i]){
			adj[find(u[i])].push_back(irw[i]);
			adj[find(v[i])].push_back(-irw[i]);
		}
		for (int j=dis.size()-1;j>=0;j--) for (auto i:srt[j]){
			if (i.first==INT_MAX){
				ret=0;
				for (int k:del) vis[k]=0;
				dfs(find(a[i.second]),b[i.second],i.second-l);
				ans[i.second]=ret;
			}else{
				onion(i.first,i.second);
			}
		}
		for (int i=l;i<=r;i++) if (t[i]==1) w[a[i]]=b[i];
	}
	for (int i=1;i<=q;i++) if (ans[i]) cout<<ans[i]<<"\n";
}

Compilation message (stderr)

bridges.cpp: In function 'int main()':
bridges.cpp:50:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |  for (int i=0;i<dis.size();i++) dd[dis[i]]=i;
      |               ~^~~~~~~~~~~
bridges.cpp:54:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |   for (int i=0;i<dis.size();i++) srt[i].clear();
      |                ~^~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 0 / 16
• Subtask 3: 0 / 17
• Subtask 4: 0 / 14
• Subtask 5: 0 / 13
• Subtask 6: 0 / 27