Submission #974733

#	Time	Username	Problem	Language	Result	Execution time	Memory
974733		happy_node	Reconstruction Project (JOI22_reconstruction)	C++17	70 / 100	5072 ms	439348 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<pair<int,int>> adj[MX];

const int inf=2e9;

array<int,3> bfs(int S, int T) {
	queue<int> q;
	q.push(S);
	
	vector<array<int,3>> dist(N+1,{-1,-1,-1});
	dist[S]={inf,inf,inf};

	while(!q.empty()) {
		auto v=q.front(); q.pop();
		for(auto [u,w]:adj[v]) {
			if(dist[u][0]!=-1) continue;

			array<int,3> cur={w,min(u,v),max(u,v)};
			dist[u]=min(cur,dist[v]);
			q.push(u);
		}
	}

	return dist[T];
}

array<int,3> BFS(int S, int T) {
	queue<int> q;
	q.push(S);
	
	vector<array<int,3>> dist(N+1,{-1,-1,-1});
	dist[S]={0,0,0};

	while(!q.empty()) {
		auto v=q.front(); q.pop();
		for(auto [u,w]:adj[v]) {
			if(dist[u][0]!=-1) continue;

			array<int,3> cur={w,min(u,v),max(u,v)};
			dist[u]=max(cur,dist[v]);
			q.push(u);
		}
	}

	return dist[T];
}

array<int,3> e[100000+5];
vector<int> PF[100000+5], SF[100000+5];

set<array<int,4>> E;
map<array<int,3>, int> id;

int L[100000+5], R[100000+5];

int main() {
	cin.tie(0); ios_base::sync_with_stdio(0);

	cin>>N>>M;

	vector<array<int,4>> edges;

	for(int i=0;i<M;i++) {
		int u,v,w;
		cin>>u>>v>>w;
		e[i]={w,u,v};
		id[e[i]]=i;
		edges.push_back({w,u,v,i});
	}		

	sort(edges.begin(),edges.end());

	int i=0;
	for(auto [w,u,v,ID]:edges) {
		auto [ww,uu,vv]=bfs(u,v);
		if(ww!=-1) {
			adj[uu].erase({vv,ww});
			adj[vv].erase({uu,ww});
			E.erase({ww,uu,vv,id[{ww,uu,vv}]});
		}
		adj[u].insert({v,w});
		adj[v].insert({u,w});
		E.insert({w,u,v,id[{w,u,v}]});
		for(auto [ww,uu,vv,id]:E) {
			PF[i].push_back(id);
		}
		reverse(PF[i].begin(),PF[i].end());

		if(ww!=-1)
			L[ID]=(w+ww),assert(ww<=w);
		else
			L[ID]=0;
		i++;
	}

	reverse(edges.begin(),edges.end());
	E.clear();
	for(int i=1;i<=N;i++) adj[i].clear();

	i=M-1;
	for(auto [w,u,v,ID]:edges) {
		auto [ww,uu,vv]=BFS(u,v);
		if(ww!=-1) {
			adj[uu].erase({vv,ww});
			adj[vv].erase({uu,ww});
			E.erase({ww,uu,vv,id[{ww,uu,vv}]});
		}
		adj[u].insert({v,w});
		adj[v].insert({u,w});
		E.insert({w,u,v,id[{w,u,v}]});
		for(auto [ww,uu,vv,id]:E) {
			SF[i].push_back(id);
		}
		
		if(ww!=-1)
			R[ID]=(w+ww),assert(ww>=w);
		else
			R[ID]=2e9+1;
		i--;
	}

	reverse(edges.begin(),edges.end());

	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:170:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  170 |   while(pa+1<add.size() && add[pa+1].first<=2*x) {
      |         ~~~~^~~~~~~~~~~
reconstruction.cpp:175:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  175 |   while(pd+1<del.size() && del[pd+1].first<=2*x) {
      |         ~~~~^~~~~~~~~~~

• Subtask 1: 3 / 3
• Subtask 2: 4 / 4
• Subtask 3: 0 / 7
• Subtask 4: 28 / 28
• Subtask 5: 35 / 35
• Subtask 6: 0 / 23