oj.uz

Submission #981221

# Submission time Handle Problem Language Result Execution time Memory
981221 2024-05-13T02:33:47 Z Lib Swapping Cities (APIO20_swap) C++14
0 / 100
 336 ms 63192 KB 
#include <bits/stdc++.h>
using namespace std;
int n,m;
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];
long long Val[500003];//the value of the i-th node of the KRT
vector <int> KRTID;
void DSU(int id, int u, int v, int w){
	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
	if(CurRep[u]==CurRep[v]){
		//The node isn't toggled just yet. Toggle it immediately
		if(!Toggle[CurRep[u]]){
			Toggle[CurRep[u]]=1;
			Val[CurRep[u]]=w;
		}else{
		//The node is already toggled by an edge with lower edge. Only a fucking dumbass would touch it - already minimized
		//toggle value. Just leave it alone
		}
	}else{
		//u and v doesn't belong to the same component. Merge them
		int CurID=n-1+id;
		int OldComp1=CurRep[u], OldComp2=CurRep[v];
		adj[CurRep[u]].push_back(CurID);
		adj[CurRep[v]].push_back(CurID);
		adj[CurID].push_back(CurRep[u]);
		adj[CurID].push_back(CurRep[v]);
		Par[CurRep[u]]=CurID;
		Par[CurRep[v]]=CurID;
		if(InComponents[u].size()>InComponents[v].size()){
			swap(u,v);
			//Small to large merging
		}
		for(int i=0;i<InComponents[u].size();i++){
			InComponents[CurID].push_back(InComponents[u][i]);
			CurRep[InComponents[u][i]]=CurID;
		}
		for(int i=0;i<InComponents[v].size();i++){
			InComponents[CurID].push_back(InComponents[v][i]);
			CurRep[InComponents[v][i]]=CurID;
		}
		Val[CurID]=w;
		//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;
		}
		KRTID.push_back(CurID);
		RootID=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<n;i++){
		CurRep[i]=i;
		InComponents[i].push_back(i);
		KRTID.push_back(i);
	}
	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;
	dq.push_back(RootID);
	Check[RootID]=1;
	int Cur;
	while(!dq.empty()){
		Cur=dq.front();
		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();
	}
	Par[RootID]=500000;
	Par[500000]=500000;
	Toggle[500000]=1;
	for(int i=0;i<=19;i++){
		for(int k=0;k<KRTID.size();k++){
			if(i==0){
				Ancestor[KRTID[k]][i]=Par[KRTID[k]];
			}else{
				Ancestor[KRTID[k]][i]=Ancestor[Ancestor[KRTID[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];
		}
	}
	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];
	}
	/*int cnt=0;
	while(!Toggle[Par[x]]&&Par[x]!=500000){
		x=Par[x];
	}*/
	for(int i=19;i>=0;i--){
		if(!Toggle[Ancestor[x][i]]){
			x=Ancestor[x][i];
		}
	}
	//x=Par[x];
	if(Toggle[x]&&x!=500000){
		return Val[x];
	}
	return -1;
}

Compilation message

swap.cpp: In function 'void DSU(int, int, int, int)':
swap.cpp:54:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |   for(int i=0;i<InComponents[u].size();i++){
      |               ~^~~~~~~~~~~~~~~~~~~~~~~
swap.cpp:58:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |   for(int i=0;i<InComponents[v].size();i++){
      |               ~^~~~~~~~~~~~~~~~~~~~~~~
swap.cpp: In function 'void init(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
swap.cpp:100:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  100 |   for(int i=0;i<adj[Cur].size();i++){
      |               ~^~~~~~~~~~~~~~~~
swap.cpp:113:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  113 |   for(int k=0;k<KRTID.size();k++){
      |               ~^~~~~~~~~~~~~
swap.cpp: In function 'int getMinimumFuelCapacity(int, int)':
swap.cpp:146:2: warning: label 'SkipPoint' defined but not used [-Wunused-label]
  146 |  SkipPoint:;
      |  ^~~~~~~~~

Subtask #1
0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 12632 KB Output is correct
2 Correct 2 ms 12632 KB Output is correct
3 Correct 2 ms 12636 KB Output is correct
4 Correct 2 ms 12892 KB Output is correct
5 Correct 2 ms 12996 KB Output is correct
6 Correct 3 ms 12828 KB Output is correct
7 Correct 2 ms 12892 KB Output is correct
8 Correct 2 ms 12892 KB Output is correct
9 Correct 96 ms 50084 KB Output is correct
10 Correct 166 ms 58508 KB Output is correct
11 Correct 117 ms 59364 KB Output is correct
12 Correct 132 ms 58916 KB Output is correct
13 Correct 116 ms 58984 KB Output is correct
14 Correct 97 ms 48160 KB Output is correct
15 Correct 235 ms 61436 KB Output is correct
16 Correct 218 ms 60112 KB Output is correct
17 Correct 229 ms 60804 KB Output is correct
18 Correct 336 ms 63192 KB Output is correct
19 Incorrect 82 ms 25404 KB Output isn't correct
20 Halted 0 ms 0 KB -

Subtask #2
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 12632 KB Output is correct
2 Correct 2 ms 12632 KB Output is correct
3 Incorrect 188 ms 62592 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #3
0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 12632 KB Output is correct
2 Correct 2 ms 12632 KB Output is correct
3 Correct 2 ms 12636 KB Output is correct
4 Correct 2 ms 12892 KB Output is correct
5 Correct 2 ms 12996 KB Output is correct
6 Correct 3 ms 12828 KB Output is correct
7 Correct 2 ms 12892 KB Output is correct
8 Correct 2 ms 12892 KB Output is correct
9 Incorrect 2 ms 12632 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 12632 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 12632 KB Output is correct
2 Correct 2 ms 12632 KB Output is correct
3 Correct 2 ms 12636 KB Output is correct
4 Correct 2 ms 12892 KB Output is correct
5 Correct 2 ms 12996 KB Output is correct
6 Correct 3 ms 12828 KB Output is correct
7 Correct 2 ms 12892 KB Output is correct
8 Correct 2 ms 12892 KB Output is correct
9 Correct 96 ms 50084 KB Output is correct
10 Correct 166 ms 58508 KB Output is correct
11 Correct 117 ms 59364 KB Output is correct
12 Correct 132 ms 58916 KB Output is correct
13 Correct 116 ms 58984 KB Output is correct
14 Correct 97 ms 48160 KB Output is correct
15 Correct 235 ms 61436 KB Output is correct
16 Correct 218 ms 60112 KB Output is correct
17 Correct 229 ms 60804 KB Output is correct
18 Correct 336 ms 63192 KB Output is correct
19 Incorrect 188 ms 62592 KB Output isn't correct
20 Halted 0 ms 0 KB -

Subtask #6
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 12632 KB Output isn't correct
2 Halted 0 ms 0 KB -