oj.uz

Submission #982396

# Submission time Handle Problem Language Result Execution time Memory
982396 2024-05-14T08:07:02 Z Lib Swapping Cities (APIO20_swap) C++14
0 / 100
 2000 ms 55732 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);
		//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;
		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(!Toggle[RootID]){
		return -1;
	}
	
	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];
	}
	while(x!=y){
		x=Par[x];
		y=Par[y];
	}
	while(!Toggle[x]&&x!=-1){
		x=Par[x];
	}
	return Val[x];
}
/*
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:97:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   97 |   for(int i=0;i<adj[Cur].size();i++){
      |               ~^~~~~~~~~~~~~~~~

Subtask #1
0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 14680 KB Output is correct
2 Correct 2 ms 14932 KB Output is correct
3 Correct 2 ms 14684 KB Output is correct
4 Correct 2 ms 14684 KB Output is correct
5 Correct 2 ms 14968 KB Output is correct
6 Correct 2 ms 14940 KB Output is correct
7 Correct 3 ms 14940 KB Output is correct
8 Correct 3 ms 14940 KB Output is correct
9 Correct 71 ms 43556 KB Output is correct
10 Correct 114 ms 50728 KB Output is correct
11 Correct 91 ms 53680 KB Output is correct
12 Correct 103 ms 52360 KB Output is correct
13 Correct 90 ms 53320 KB Output is correct
14 Correct 67 ms 46288 KB Output is correct
15 Correct 132 ms 54956 KB Output is correct
16 Correct 119 ms 54444 KB Output is correct
17 Correct 132 ms 53668 KB Output is correct
18 Correct 117 ms 53672 KB Output is correct
19 Correct 64 ms 23444 KB Output is correct
20 Correct 154 ms 54052 KB Output is correct
21 Correct 154 ms 51440 KB Output is correct
22 Correct 160 ms 55732 KB Output is correct
23 Execution timed out 2037 ms 53652 KB Time limit exceeded
24 Halted 0 ms 0 KB -

Subtask #2
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 14680 KB Output is correct
2 Correct 2 ms 14932 KB Output is correct
3 Execution timed out 2057 ms 54932 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #3
0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 14680 KB Output is correct
2 Correct 2 ms 14932 KB Output is correct
3 Correct 2 ms 14684 KB Output is correct
4 Correct 2 ms 14684 KB Output is correct
5 Correct 2 ms 14968 KB Output is correct
6 Correct 2 ms 14940 KB Output is correct
7 Correct 3 ms 14940 KB Output is correct
8 Correct 3 ms 14940 KB Output is correct
9 Incorrect 2 ms 14696 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 14696 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 14680 KB Output is correct
2 Correct 2 ms 14932 KB Output is correct
3 Correct 2 ms 14684 KB Output is correct
4 Correct 2 ms 14684 KB Output is correct
5 Correct 2 ms 14968 KB Output is correct
6 Correct 2 ms 14940 KB Output is correct
7 Correct 3 ms 14940 KB Output is correct
8 Correct 3 ms 14940 KB Output is correct
9 Correct 71 ms 43556 KB Output is correct
10 Correct 114 ms 50728 KB Output is correct
11 Correct 91 ms 53680 KB Output is correct
12 Correct 103 ms 52360 KB Output is correct
13 Correct 90 ms 53320 KB Output is correct
14 Correct 67 ms 46288 KB Output is correct
15 Correct 132 ms 54956 KB Output is correct
16 Correct 119 ms 54444 KB Output is correct
17 Correct 132 ms 53668 KB Output is correct
18 Correct 117 ms 53672 KB Output is correct
19 Execution timed out 2057 ms 54932 KB Time limit exceeded
20 Halted 0 ms 0 KB -

Subtask #6
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 14696 KB Output isn't correct
2 Halted 0 ms 0 KB -