oj.uz

Submission #982420

# Submission time Handle Problem Language Result Execution time Memory
982420 2024-05-14T08:27:26 Z Lib Swapping Cities (APIO20_swap) C++14
7 / 100
 240 ms 56520 KB 
#include <bits/stdc++.h>
using namespace std;
int n,m,a,b,c;
vector <vector <int> > InComponents;
vector <vector <int> > adj; //the edge list of the KRT
vector <int> TVector;
int RootID; //ID of the root node of the KRT;
struct Edge{
	long long Weight;
	int Start;
	int End;
};
bool operator< (const Edge &x, const Edge &y){
	return x.Weight<y.Weight;
}
Edge Elist[500003];
int Depth[500003];
int Deg[500003];
int CurRep[500003]; //id of the respresentative node on the KRT
int Par[500003]; //Parent of node with id i on the KRT;
int Toggle[500003]; //is the i-th node on the KRT toggled?
int Check[500003];
int Ancestor[500003][20];
int Val[500003];//the value of the i-th node of the KRT
vector <int> KRTID;
int GetRep(int u){
	if(CurRep[u]==-1){
		return u;
	}else{
		return CurRep[u]=GetRep(CurRep[u]);
	}
}
void DSU(int id, int u, int v, int w){
	int CurID=n-1+id;
	Deg[u]++;
	Deg[v]++;
	//u and v belongs to the same component. The component now has a cycle. Immediately toggle the root node of the current 
	//subtree that includes both u and v on the KRT
	//Screw partial, binary tree KRT, opt into full-KRT instead
	int RepU=GetRep(u), RepV=GetRep(v);
	if(RepU==RepV){
		Par[RepU]=CurID;
		Val[CurID]=w;
		adj[RepU].push_back(CurID);
		adj[CurID].push_back(RepU);
		CurRep[RepU]=CurID;
		//The node isn't toggled just yet. Toggle it immediately as there is a cycle
		Toggle[CurID]=1;
	}else{
		//u and v doesn't belong to the same component. Merge them
		int OldComp1=RepU, OldComp2=RepV;
		adj[RepU].push_back(CurID);
		adj[RepV].push_back(CurID);
		adj[CurID].push_back(RepU);
		adj[CurID].push_back(RepV);
		Par[RepU]=CurID;
		Par[RepV]=CurID;
		CurRep[RepU]=CurID;
		CurRep[RepV]=CurID;
		Val[CurID]=w; //if I got WA because I forgot to set the fucking node weight to the nodes on the KRT, I'll shove 3 fingers up my ass.
		//if either of the components are toggled already (having a cycle OR a vertex with degree >=3)
		//OR the merged component has a vertex with degree >3 (either u or v), toggle immediately
		if(Toggle[OldComp1]||Toggle[OldComp2]||Deg[u]>2||Deg[v]>2){
			Toggle[CurID]=1;
		}
	}
	//cout<<CurID<<" ";
}
void init(int N, int M, vector <int> U, vector <int> V, vector <int> W){
	n=N;
	m=M;
	for(int i=0;i<n+m+5;i++){
		InComponents.push_back(TVector);
		adj.push_back(TVector);
	}
	for(int i=1;i<=m;i++){
		Elist[i].Weight=W[i-1];
		Elist[i].Start=U[i-1];
		Elist[i].End=V[i-1];
	}
	sort(Elist+1,Elist+m+1);
	for(int i=0;i<=m+n+1;i++){
		CurRep[i]=-1;
		Par[i]=-1;
		Toggle[i]=0;
	}		
	for(int i=1;i<=m;i++){
		DSU(i,Elist[i].Start,Elist[i].End,Elist[i].Weight);
	}
	//The KRT is now built. BFS from the root node and initialize LCA or something
	deque <int> dq;
	RootID=n+m-1;
	dq.push_back(RootID);
	Check[RootID]=1;
	int Cur;
	while(!dq.empty()){
		Cur=dq.front();
		//cout<<Cur<<" ";
		for(int i=0;i<adj[Cur].size();i++){
			if(!Check[adj[Cur][i]]){
				dq.push_back(adj[Cur][i]);
				Check[adj[Cur][i]]=1;
				Depth[adj[Cur][i]]=Depth[Cur]+1;
			}
		}
		dq.pop_front();
	}
	for(int i=0;i<=19;i++){
		for(int k=0;k<n+m;k++){
			if(i==0){
				Ancestor[k][i]=Par[k];
			}else{
				Ancestor[k][i]=Ancestor[Ancestor[k][i-1]][i-1];
			}
		}
	}
}
int getMinimumFuelCapacity(int x, int y){
	//I thought that we actually need to use binary lifting to find LCA and then jump from the LCA to find the nearest
	//toggled node on the KRT
	//But apparently small-to-large merging ensures that the depth of the tree is always logN or something, so bruteforcing
	//it is
	//ok nvm this guy is a fucking moron lmao LogN depth my ass. Wrong analysis, wasted 5 minutes. Fuck me
	
	if(Depth[x]<Depth[y]){
		swap(x,y);
	}

	int JumpLevel=Depth[x]-Depth[y];
	for(int i=19;i>=0;i--){
		if(JumpLevel >> i & 1){
			x=Ancestor[x][i];
		}
	}
	if(x==y){
		goto SkipPoint;
	}
	for(int i=19;i>=0;i--){
		if(Ancestor[x][i]!=Ancestor[y][i]){
			x=Ancestor[x][i];
			y=Ancestor[y][i];
		}
	}
	x=Par[x];
	y=Par[y];
	SkipPoint:;
	if(Toggle[x]){
		return Val[x];
	}
	for(int i=19;i>=0;i--){
		if(!Toggle[Ancestor[x][i]]){
			x=Ancestor[x][i];
		}
	}
	x=Par[x];
	if(Toggle[x]&&x!=-1){
		return Val[x];
	}
	return -1;
	
	/*
	while(Depth[x]>Depth[y]){
		x=Par[x];
	}
	if(x==y){
		goto SkipPoint;
	}
	while(x!=y){
		x=Par[x];
		y=Par[y];
	}
	SkipPoint:
	while(!Toggle[x]&&x!=-1){
		x=Par[x];
	}
	if(x!=-1){
		return Val[x];
	}else{
		return -1;
	}
	*/
}
/*
int q;
int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	freopen("swap_12_2.in","r",stdin);
	cin>>n>>m;
	vector <int> U,V,W;
	for(int i=1;i<=m;i++){
		cin>>a>>b>>c;
		U.push_back(a);
		V.push_back(b);
		W.push_back(c);
	}
	init(n,m,U,V,W);
	deque <int> dq;
	cin>>q;
	for(int i=1;i<=q;i++){
		cin>>a>>b;
		dq.push_back(getMinimumFuelCapacity(a,b));
		cout<<dq.back()<<"\n";
	}
	freopen("swap_12_2.out","r",stdin);
	int cur, score=0;
	for(int i=1;i<=q;i++){
		cin>>cur;
		if(cur==dq.front()){
			score++;
		}else{
			cout<<dq.front()<<" "<<cur<<" "<<Val[RootID]<<"\n";
		}
		dq.pop_front();
	}
	cout<<score<<" "<<q<<" ";
	int maxdepth=0;
	for(int i=0;i<=n+m+5;i++){
		maxdepth=max(maxdepth,Depth[i]);
	}
	//cout<<maxdepth;
}
*/
/*
5 6
0 1 4
0 2 4
1 2 1
1 3 2
1 4 10
2 3 3
*/

Compilation message

swap.cpp: In function 'void init(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
swap.cpp:99:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   99 |   for(int i=0;i<adj[Cur].size();i++){
      |               ~^~~~~~~~~~~~~~~~

Subtask #1
0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 14684 KB Output is correct
2 Correct 2 ms 14684 KB Output is correct
3 Correct 2 ms 14684 KB Output is correct
4 Correct 2 ms 14684 KB Output is correct
5 Correct 3 ms 14940 KB Output is correct
6 Correct 2 ms 14940 KB Output is correct
7 Correct 2 ms 14940 KB Output is correct
8 Correct 3 ms 14940 KB Output is correct
9 Correct 72 ms 47404 KB Output is correct
10 Correct 84 ms 53492 KB Output is correct
11 Correct 89 ms 53792 KB Output is correct
12 Correct 92 ms 51736 KB Output is correct
13 Correct 83 ms 52248 KB Output is correct
14 Correct 89 ms 46104 KB Output is correct
15 Correct 181 ms 55212 KB Output is correct
16 Correct 171 ms 52176 KB Output is correct
17 Correct 217 ms 55204 KB Output is correct
18 Correct 240 ms 53612 KB Output is correct
19 Incorrect 79 ms 23100 KB Output isn't correct
20 Halted 0 ms 0 KB -

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 14684 KB Output is correct
2 Correct 2 ms 14684 KB Output is correct
3 Correct 154 ms 53304 KB Output is correct
4 Correct 165 ms 54308 KB Output is correct
5 Correct 204 ms 53944 KB Output is correct
6 Correct 161 ms 54216 KB Output is correct
7 Correct 175 ms 55792 KB Output is correct
8 Correct 152 ms 56520 KB Output is correct
9 Correct 161 ms 53664 KB Output is correct
10 Correct 158 ms 52840 KB Output is correct

Subtask #3
0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 14684 KB Output is correct
2 Correct 2 ms 14684 KB Output is correct
3 Correct 2 ms 14684 KB Output is correct
4 Correct 2 ms 14684 KB Output is correct
5 Correct 3 ms 14940 KB Output is correct
6 Correct 2 ms 14940 KB Output is correct
7 Correct 2 ms 14940 KB Output is correct
8 Correct 3 ms 14940 KB Output is correct
9 Incorrect 2 ms 14684 KB Output isn't correct
10 Halted 0 ms 0 KB -

Subtask #4
0 / 20.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 14684 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 14684 KB Output is correct
2 Correct 2 ms 14684 KB Output is correct
3 Correct 2 ms 14684 KB Output is correct
4 Correct 2 ms 14684 KB Output is correct
5 Correct 3 ms 14940 KB Output is correct
6 Correct 2 ms 14940 KB Output is correct
7 Correct 2 ms 14940 KB Output is correct
8 Correct 3 ms 14940 KB Output is correct
9 Correct 72 ms 47404 KB Output is correct
10 Correct 84 ms 53492 KB Output is correct
11 Correct 89 ms 53792 KB Output is correct
12 Correct 92 ms 51736 KB Output is correct
13 Correct 83 ms 52248 KB Output is correct
14 Correct 89 ms 46104 KB Output is correct
15 Correct 181 ms 55212 KB Output is correct
16 Correct 171 ms 52176 KB Output is correct
17 Correct 217 ms 55204 KB Output is correct
18 Correct 240 ms 53612 KB Output is correct
19 Correct 154 ms 53304 KB Output is correct
20 Correct 165 ms 54308 KB Output is correct
21 Correct 204 ms 53944 KB Output is correct
22 Correct 161 ms 54216 KB Output is correct
23 Correct 175 ms 55792 KB Output is correct
24 Correct 152 ms 56520 KB Output is correct
25 Correct 161 ms 53664 KB Output is correct
26 Correct 158 ms 52840 KB Output is correct
27 Correct 3 ms 14936 KB Output is correct
28 Correct 2 ms 14940 KB Output is correct
29 Correct 3 ms 14940 KB Output is correct
30 Correct 3 ms 14940 KB Output is correct
31 Correct 2 ms 14940 KB Output is correct
32 Incorrect 2 ms 14936 KB Output isn't correct
33 Halted 0 ms 0 KB -

Subtask #6
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 14684 KB Output isn't correct
2 Halted 0 ms 0 KB -