Submission #568728

#	Time	Username	Problem	Language	Result	Execution time	Memory
568728		errorgorn	Reconstruction Project (JOI22_reconstruction)	C++17	42 / 100	5056 ms	23784 KiB

reconstruction

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define ii pair<int,int>
#define fi first
#define se second
#define endl '\n'

#define puf push_front
#define pof pop_front
#define pub push_back
#define pob pop_back
#define lb lower_bound
#define ub upper_bound

#define rep(x,s,e) for (int x=(s)-((s)>(e));x!=(e)-((s)>(e));((s)<(e))?x++:x--)
#define all(x) (x).begin(),(x).end()
#define sz(x) (int) (x).size()

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

struct UFDS{
	int p[505];
	int r[505];
	
	void reset(){ rep(x,0,505) p[x]=x,r[x]=0; }
	
	int par(int i){
		if (p[i]==i) return i;
		else return p[i]=par(p[i]);
	}
	
	bool unions(int i,int j){
		i=par(i),j=par(j);
		if (i==j) return false;
		
		if (r[i]>r[j]) swap(i,j);
		p[i]=j;
		if (r[i]==r[j]) r[j]++;
		
		return true;
	}
} ufds;

int n,m,q;
struct E{
	int u,v;
	int w;
};

E ee[100005];

int qu[1000005];
int split[1000005];
int ans[1000005];

void solve(int l,int r,int optl,int optr,vector<int> vl,vector<int> vr){
	int m=l+r>>1;
	
	//[optl,split[m]-1]
	//[split[m],optr]
	
	vector<int> tl=vl,tr=vr;
	vector<int> vl2,vr2;
	
	rep(x,optl,split[m]) tl.pub(x);
	rep(x,optr+1,split[m]) tr.pub(x);
	
	//cout<<"debug: "<<l<<" "<<m<<" "<<r<<" "<<optl<<" "<<optr<<endl;
	//for (auto it:tl) cout<<it<<" "; cout<<endl;
	//for (auto it:tr) cout<<it<<" "; cout<<endl;
	
	ufds.reset();
	while (sz(vl2)+sz(vr2)!=n-1){ //mst is not complete
		if (tr.empty() || 
			(!tl.empty() && qu[m]-ee[tl.back()].w<=ee[tr.back()].w-qu[m])){
			
			if (ufds.unions(ee[tl.back()].u,ee[tl.back()].v)){
				ans[m]+=qu[m]-ee[tl.back()].w;
				vl2.pub(tl.back());
			}
			tl.pob();
		}
		else{
			if (ufds.unions(ee[tr.back()].u,ee[tr.back()].v)){
				ans[m]+=ee[tr.back()].w-qu[m];
				vr2.pub(tr.back());
			}
			tr.pob();
		}
	}
	
	reverse(all(vl2));
	reverse(all(vr2));
	
	//for (auto it:vl2) cout<<it<<" "; cout<<endl;
	//for (auto it:vr2) cout<<it<<" "; cout<<endl;
	
	if (l!=m) solve(l,m-1,optl,split[m]-1,vl,vr2);
	if (m!=r) solve(m+1,r,split[m],optr,vl2,vr);
}

signed main(){
	cin.tie(0);
	cout.tie(0);
	cin.sync_with_stdio(false);
	
	cin>>n>>m;
	rep(x,0,m) cin>>ee[x].u>>ee[x].v>>ee[x].w;
	
	sort(ee,ee+m,[](E i,E j){
		return i.w<j.w;
	});
	
	cin>>q;
	rep(x,0,q) cin>>qu[x];
	
	split[0]=0;
	rep(x,0,q){
		while (split[x]<m && ee[split[x]].w<=qu[x]) split[x]++;
		split[x+1]=split[x];
	}
	
	//rep(x,0,m) cout<<x<<" "; cout<<endl;
	//rep(x,0,m) cout<<ee[x].u<<" "; cout<<endl;
	//rep(x,0,m) cout<<ee[x].v<<" "; cout<<endl;
	//rep(x,0,m) cout<<ee[x].w<<" "; cout<<endl;
	//cout<<endl;
	
	//rep(x,0,q) cout<<qu[x]<<" "; cout<<endl;
	//rep(x,0,q) cout<<split[x]<<" "; cout<<endl;
	
	solve(0,q-1,0,m-1,{},{});
	
	rep(x,0,q) cout<<ans[x]<<endl;
}

Compilation message (stderr)

reconstruction.cpp: In function 'void solve(long long int, long long int, long long int, long long int, std::vector<long long int>, std::vector<long long int>)':
reconstruction.cpp:59:9: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   59 |  int m=l+r>>1;
      |        ~^~

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