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Submission #1056614

# Submission time Handle Problem Language Result Execution time Memory
1056614 2024-08-13T10:19:45 Z d(#11110) Summer Driving (CCO24_day1problem3) C++17
9 / 25
 32 ms 15452 KB 
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...)
#endif
using pii=array<int,2>;
using tii=array<int,3>;
using ti4=array<int,4>;
const int N=3005;
int n,r,a,b,dep[N],p[N],q[N],L[N],pA[N],subA[N];
int sz[N],in[N],inv[N],out[N],C,ctop[N];
vector<int> dp[N],dp2[N];
set<pii> S[2][N];
vector<int> g[N],c[N],dL[N];
vector<int> dA[N],idxsubA[N];
vector<int> up[N],invup[N];
vector<pii> ev[N];
vector<ti4> qry[N];
struct SEG{
	int T[2*N];
	void init(int nd,int l,int r){
		T[nd]=(int)1e9;
		if(l==r) return;
		int m=(l+r)>>1,ln=nd+1,rn=nd+2*(m-l+1);
		init(ln,l,m); init(rn,m+1,r);
	}
	void upd(int nd,int l,int r,int x,int v){
		T[nd]=min(T[nd],v);
		if(l==r) return;
		int m=(l+r)>>1,ln=nd+1,rn=nd+2*(m-l+1);
		if(x<=m) upd(ln,l,m,x,v);
		else upd(rn,m+1,r,x,v);
	}
	int qry(int nd,int l,int r,int s,int e){
		if(r<s||e<l) return (int)1e9;
		if(s<=l&&r<=e) return T[nd];
		int m=(l+r)>>1,ln=nd+1,rn=nd+2*(m-l+1);
		return min(qry(ln,l,m,s,e),qry(rn,m+1,r,s,e));
	}
}T;
void dfs0(int u){
	L[dep[u]]=u;
	dL[dep[u]].push_back(u);
	if(dep[u]>=a){
		pA[u]=L[dep[u]-a];
		subA[u]=L[dep[u]-a+1];
		idxsubA[subA[u]].push_back(dA[pA[u]].size());
		dA[pA[u]].push_back(u);
	}
	sz[u]=1;
	for(int v: g[u]) if(p[u]!=v){
		dep[v]=dep[u]+1;
		p[v]=u;
		c[u].push_back(v);
		dfs0(v);
		sz[u]+=sz[v];
	}
}
void dfsH(int u,int t){
	in[u]=++C;
	inv[in[u]]=u;
	ctop[u]=t;
	int idx=0;
	for(int v: c[u]){
		q[v]=++idx;
		if(v==c[u][0]) dfsH(v,t);
		else dfsH(v,v);
	}
	out[u]=C;
}
struct ErasableSet{
	priority_queue<int> pq1,pq2;
	void insert(int x){
		pq1.push(x);
	}
	void erase(int x){
		pq2.push(x);
	}
	int top(){
		while(pq2.size()&&pq1.top()==pq2.top()){
			pq1.pop();
			pq2.pop();
		}
		return pq1.top();
	}
	int size(){
		return pq1.size()-pq2.size();
	}
}dp2C[N];
void ins(int c,int u,pii p){
	auto iter=S[c][u].lower_bound(p);
	while(iter!=S[c][u].end()&&p[1]<=(*iter)[1]) iter=S[c][u].erase(iter);
	if(iter!=S[c][u].begin()){
		iter--;
		if((*iter)[1]<=p[1]) return;
	}
	S[c][u].insert(p);
}
void mrg(int c,int u,int v){
	if(S[c][u].size()<S[c][v].size()) swap(S[c][u],S[c][v]);
	for(pii p: S[c][v]) ins(c,u,p);
}
int dp3[N][N];
int dfs1(int u,int d){
	int &ret=dp3[u][d];
	if(ret) return ret;
	ret=dp[u][0];
	if(d>=1) for(int v: c[u]) ret=min(ret,dfs1(v,d-1));
	return ret;
}
int main(){
	ios::sync_with_stdio(false); cin.tie(0);
	cin>>n>>r>>a>>b;
	if(a<=b){
		cout<<"1\n";
		return 0;
	}
	for(int u,v,i=1;i<n;i++){
		cin>>u>>v;
		g[u].push_back(v);
		g[v].push_back(u);
	}
	dfs0(r);
	for(int u=1;u<=n;u++){
		for(int &v: c[u]) if(sz[v]>sz[c[u][0]]) swap(v,c[u][0]);
	}
	dfsH(r,r);
	for(int i=1;i<=n;i++){
		dp[i].resize(c[i].size()+1);
		dp2[i].resize(dA[i].size());
	}
	for(int i=1;i<=n;i++){
		int u=i;
		while(u){
			if(dep[i]-dep[u]>b) break;
			if(u!=i){
				up[i].push_back(u);
				invup[u].push_back(i);
				if(dep[u]-a+b-(dep[i]-dep[u])>=0) ev[dep[u]-a+b-(dep[i]-dep[u])].push_back({i,u});
			}
			u=p[ctop[u]];
		}
	}
	T.init(1,1,n);
	for(int D=n;D>=0;D--){
		for(int u: dL[D]){
			for(int i=0;i<(int)dA[u].size();i++){
				int v=dA[u][i],w=v,e=0;
				dp2[u][i]=(int)1e9;
				while(w){
					if(dep[v]-dep[w]>b) break;
					int ww=ctop[w];
					if(dep[v]-dep[ww]>b) ww=inv[in[ww]+(dep[v]-dep[ww]-b)];
					int d=dep[v]-dep[w];
					if(d<b) qry[w].push_back({e,b-d,u,i});
					e=q[ww];
					w=p[ww];
				}
			}
		}
	}
	for(int D=n;D>=0;D--){
		for(auto [u,v]: ev[D]) T.upd(1,1,n,in[v],dp[u][0]);
		for(int u: dL[D]){
			for(int i=0;i<(int)dA[u].size();i++){
				int v=dA[u][i];
				int &ret=dp2[u][i],w=v,e=0;
				while(w){
					if(dep[v]-dep[w]>b) break;
					int ww=ctop[w];
					if(dep[v]-dep[ww]>b) ww=inv[in[ww]+(dep[v]-dep[ww]-b)];
					if(in[ww]<=in[w]-1) ret=min(ret,T.qry(1,1,n,in[ww],in[w]-1));
					ret=min(ret,dp[w][e]);
					e=q[ww];
					w=p[ww];
				}
				dp2C[u].insert(dp2[u][i]);
			}
			for(int k=0;k<=(int)c[u].size();k++){
				int &ret=dp[u][k];
				if(dA[u].empty()||(k&&dA[u].size()==idxsubA[c[u][k-1]].size())){
					if(k&&idxsubA[c[u][k-1]].empty()) ret=dp[u][0];
					else{
						ret=u;
						for(int i=0;i<(int)c[u].size();i++) if(i+1!=k){
							auto iter=S[0][c[u][i]].lower_bound({dep[u]+b,(int)1e9});
							iter--;
							ret=min(ret,(*iter)[1]);
						}
					}
				} else{
					if(k){
						for(int i: idxsubA[c[u][k-1]]){
							dp2C[u].erase(dp2[u][i]);
						}
					}
					ret=dp2C[u].top();
					if(k){
						for(int i: idxsubA[c[u][k-1]]) dp2C[u].insert(dp2[u][i]);
					}
				}
			}
			sort(qry[u].begin(),qry[u].end());
			for(auto [e,d,v,i]: qry[u]){
				for(int j=0;j<(int)c[u].size();j++) if(j+1!=e){
					dp2[v][i]=min(dp2[v][i],dfs1(c[u][j],d-1));
				}
			}
			int prv=0;
			for(auto [e,d,v,i]: qry[u]) if(e>1){
				e--;
				while(prv+1<e){
					prv++;
					set<pii> SS=S[1][c[u][prv]];
					mrg(1,u,c[u][prv]);
					S[1][c[u][prv]]=SS;
				}
				auto iter=S[1][u].lower_bound({dep[u]+d,(int)1e9});
				if(iter==S[1][u].begin()) continue;
				iter--;
				dp2[v][i]=min(dp2[v][i],(*iter)[1]);
			}
			S[1][u].clear();
			reverse(qry[u].begin(),qry[u].end());
			prv=c[u].size();
			for(auto [e,d,v,i]: qry[u]){
				e--;
				while(prv-1>e){
					prv--;
					mrg(1,u,c[u][prv]);
				}
				auto iter=S[1][u].lower_bound({dep[u]+d,(int)1e9});
				if(iter==S[1][u].begin()) continue;
				iter--;
				dp2[v][i]=min(dp2[v][i],(*iter)[1]);
			}
			while(prv>0){
				prv--;
				mrg(1,u,c[u][prv]);
			}
			ins(0,u,{dep[u],u});
			ins(1,u,{dep[u],dp[u][0]});
			for(int v: c[u]) mrg(0,u,v);
			if(c[u].size()) T.upd(1,1,n,in[u],dp[u][1]);
		}
	}
	cout<<dp[r][0];
	return 0;
}

Subtask #1
1.0 / 1.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1628 KB Output is correct
2 Correct 0 ms 1628 KB Output is correct
3 Correct 0 ms 1628 KB Output is correct
4 Correct 1 ms 1628 KB Output is correct
5 Correct 1 ms 1628 KB Output is correct

Subtask #2
0.0 / 4.0

# Verdict Execution time Memory Grader output
1 Runtime error 2 ms 2904 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #3
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2908 KB Output is correct
2 Correct 1 ms 2908 KB Output is correct
3 Correct 1 ms 2652 KB Output is correct
4 Correct 1 ms 2908 KB Output is correct
5 Correct 1 ms 2652 KB Output is correct
6 Correct 1 ms 2908 KB Output is correct
7 Correct 1 ms 2908 KB Output is correct
8 Correct 1 ms 1628 KB Output is correct
9 Correct 0 ms 1628 KB Output is correct
10 Correct 1 ms 2140 KB Output is correct
11 Correct 1 ms 2908 KB Output is correct
12 Correct 0 ms 1628 KB Output is correct
13 Correct 1 ms 1628 KB Output is correct

Subtask #4
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2908 KB Output is correct
2 Correct 1 ms 2908 KB Output is correct
3 Correct 1 ms 2652 KB Output is correct
4 Correct 1 ms 2908 KB Output is correct
5 Correct 1 ms 2652 KB Output is correct
6 Correct 1 ms 2908 KB Output is correct
7 Correct 1 ms 2908 KB Output is correct
8 Correct 1 ms 1628 KB Output is correct
9 Correct 0 ms 1628 KB Output is correct
10 Correct 1 ms 2140 KB Output is correct
11 Correct 1 ms 2908 KB Output is correct
12 Correct 0 ms 1628 KB Output is correct
13 Correct 1 ms 1628 KB Output is correct
14 Correct 10 ms 14428 KB Output is correct
15 Correct 8 ms 14684 KB Output is correct
16 Correct 12 ms 14172 KB Output is correct
17 Correct 8 ms 14672 KB Output is correct
18 Correct 8 ms 13916 KB Output is correct
19 Correct 8 ms 14680 KB Output is correct
20 Correct 8 ms 14720 KB Output is correct
21 Correct 2 ms 2280 KB Output is correct
22 Correct 1 ms 1624 KB Output is correct
23 Correct 8 ms 11892 KB Output is correct
24 Correct 9 ms 14684 KB Output is correct
25 Correct 10 ms 14656 KB Output is correct
26 Correct 3 ms 2396 KB Output is correct
27 Correct 2 ms 2396 KB Output is correct
28 Correct 2 ms 2396 KB Output is correct
29 Correct 2 ms 2396 KB Output is correct
30 Correct 26 ms 10644 KB Output is correct
31 Correct 26 ms 10588 KB Output is correct
32 Correct 32 ms 10588 KB Output is correct
33 Correct 14 ms 15452 KB Output is correct

Subtask #5
0.0 / 4.0

# Verdict Execution time Memory Grader output
1 Runtime error 2 ms 2908 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #6
0.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2908 KB Output is correct
2 Correct 1 ms 2908 KB Output is correct
3 Correct 1 ms 2652 KB Output is correct
4 Correct 1 ms 2908 KB Output is correct
5 Correct 1 ms 2652 KB Output is correct
6 Correct 1 ms 2908 KB Output is correct
7 Correct 1 ms 2908 KB Output is correct
8 Correct 1 ms 1628 KB Output is correct
9 Correct 0 ms 1628 KB Output is correct
10 Correct 1 ms 2140 KB Output is correct
11 Correct 1 ms 2908 KB Output is correct
12 Correct 0 ms 1628 KB Output is correct
13 Correct 1 ms 1628 KB Output is correct
14 Correct 10 ms 14428 KB Output is correct
15 Correct 8 ms 14684 KB Output is correct
16 Correct 12 ms 14172 KB Output is correct
17 Correct 8 ms 14672 KB Output is correct
18 Correct 8 ms 13916 KB Output is correct
19 Correct 8 ms 14680 KB Output is correct
20 Correct 8 ms 14720 KB Output is correct
21 Correct 2 ms 2280 KB Output is correct
22 Correct 1 ms 1624 KB Output is correct
23 Correct 8 ms 11892 KB Output is correct
24 Correct 9 ms 14684 KB Output is correct
25 Correct 10 ms 14656 KB Output is correct
26 Correct 3 ms 2396 KB Output is correct
27 Correct 2 ms 2396 KB Output is correct
28 Correct 2 ms 2396 KB Output is correct
29 Correct 2 ms 2396 KB Output is correct
30 Correct 26 ms 10644 KB Output is correct
31 Correct 26 ms 10588 KB Output is correct
32 Correct 32 ms 10588 KB Output is correct
33 Correct 14 ms 15452 KB Output is correct
34 Runtime error 2 ms 3164 KB Execution killed with signal 11
35 Halted 0 ms 0 KB -

Subtask #7
0.0 / 2.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1628 KB Output is correct
2 Correct 0 ms 1628 KB Output is correct
3 Correct 0 ms 1628 KB Output is correct
4 Correct 1 ms 1628 KB Output is correct
5 Correct 1 ms 1628 KB Output is correct
6 Runtime error 2 ms 2904 KB Execution killed with signal 11
7 Halted 0 ms 0 KB -