Submission #974744

#	Time	Username	Problem	Language	Result	Execution time	Memory
974744		happy_node	Reconstruction Project (JOI22_reconstruction)	C++17	100 / 100	3726 ms	29116 KiB

reconstruction

#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
const int MX=505;
 
int N,M,Q;
 
struct DSU {
	int par[MX],sz[MX];
 
	int fd(int v) {
		return par[v]==v?v:par[v]=fd(par[v]);
	}
 
	bool merge(int u, int v) {
		u=fd(u),v=fd(v);
		if(u==v) return false;
		if(sz[u]>sz[v]) swap(u,v);
		par[u]=v;
		sz[v]+=sz[u];
		return true;
	}
 
	void reset() {
		for(int i=1;i<=N;i++) par[i]=i,sz[i]=1;
	}
} ds;
 
set<array<int,3>> adj[MX];
 
const int inf=2e9;

pair<int,int> dist[MX];
 
pair<int,int> bfs(int S, int T) {
	queue<int> q;
	q.push(S);

	for(int i=1;i<=N;i++) dist[i]={-1,-1};
	dist[S]={inf,inf};
 
	while(!q.empty()) {
		auto v=q.front(); q.pop();
		if(v==T) break;
		for(auto [u,w,ii]:adj[v]) {
			if(dist[u].first!=-1) continue;
 
			dist[u]=min(make_pair(w,ii),dist[v]);
			q.push(u);
		}
	}
 
	return dist[T];
}
 
pair<int,int> BFS(int S, int T) {
	queue<int> q;
	q.push(S);
	
	for(int i=1;i<=N;i++) dist[i]={-1,-1};
	dist[S]={0,0};
 
	while(!q.empty()) {
		auto v=q.front(); q.pop();
		if(v==T) break;
		for(auto [u,w,ii]:adj[v]) {
			if(dist[u].first!=-1) continue;
 
			dist[u]=max(make_pair(w,ii),dist[v]);
			q.push(u);
		}
	}
 
	return dist[T];
}
 
array<int,3> e[100000+5];
set<array<int,4>> E;
 
int L[100000+5], R[100000+5];
 
int main() {
	cin.tie(0); ios_base::sync_with_stdio(0);
 
	cin>>N>>M;
 
	for(int i=0;i<M;i++) {
		int u,v,w;
		cin>>u>>v>>w;
		e[i]={w,u,v};
	}

	sort(e,e+M);
 
	for(int i=0;i<M;i++) {
		auto [w,u,v]=e[i];

		auto [ww,ii]=bfs(u,v);
		auto [zz,uu,vv]=e[ii];

		if(ww!=-1) {
			adj[uu].erase({vv,ww,ii});
			adj[vv].erase({uu,ww,ii});
			E.erase({ww,uu,vv,ii});
		}

		adj[u].insert({v,w,i});
		adj[v].insert({u,w,i});
		E.insert({w,u,v,i});
 
		if(ww!=-1)
			L[i]=(w+ww),assert(ww<=w);
		else
			L[i]=0;
	}
 
	E.clear();
	for(int i=1;i<=N;i++) adj[i].clear();
 
	for(int i=M-1;i>=0;i--) {
		auto [w,u,v]=e[i];

		auto [ww,ii]=BFS(u,v);
		auto [zz,uu,vv]=e[ii];

		if(ww!=-1) {
			adj[uu].erase({vv,ww,ii});
			adj[vv].erase({uu,ww,ii});
			E.erase({ww,uu,vv,ii});
		}
		adj[u].insert({v,w,i});
		adj[v].insert({u,w,i});
		E.insert({w,u,v,i});

		if(ww!=-1)
			R[i]=(w+ww),assert(ww>=w);
		else
			R[i]=2e9+1;
	}
 
	vector<pair<int,int>> add, del;
 
	for(int i=0;i<M;i++) {
		add.push_back({L[i],i});
		del.push_back({R[i],i});
	}
 
	sort(add.begin(),add.end());
	sort(del.begin(),del.end());
 
	int pa=-1,pd=-1;
	set<int> curEdges;
 
	cin>>Q;
	for(int i=0;i<Q;i++) {
		ll x;
		cin>>x;
 
		while(pa+1<add.size() && add[pa+1].first<=2*x) {
			curEdges.insert(add[pa+1].second);
			pa++;
		} 
 
		while(pd+1<del.size() && del[pd+1].first<=2*x) {
			curEdges.erase(del[pd+1].second);
			pd++;
		}
 
		ll res=0;
		for(auto y:curEdges) res+=abs(e[y][0]-x);
 
		cout<<res<<'\n';
	}
}

Compilation message (stderr)

reconstruction.cpp: In function 'int main()':
reconstruction.cpp:160:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  160 |   while(pa+1<add.size() && add[pa+1].first<=2*x) {
      |         ~~~~^~~~~~~~~~~
reconstruction.cpp:165:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  165 |   while(pd+1<del.size() && del[pd+1].first<=2*x) {
      |         ~~~~^~~~~~~~~~~

• Subtask 1: 3 / 3
• Subtask 2: 4 / 4
• Subtask 3: 7 / 7
• Subtask 4: 28 / 28
• Subtask 5: 35 / 35
• Subtask 6: 23 / 23