oj.uz

Submission #982047

# Submission time Handle Problem Language Result Execution time Memory
982047 2024-05-13T18:20:08 Z Lib Swapping Cities (APIO20_swap) C++14
0 / 100
 232 ms 57192 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;
int GetRep(int u){
	if(CurRep[u]==u){
		return u;
	}else{
		return CurRep[u]=GetRep(CurRep[u]);
	}
}
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
	int RepU=GetRep(u), RepV=GetRep(v);
	if(RepU==RepV){
		//The node isn't toggled just yet. Toggle it immediately
		if(!Toggle[RepU]){
			Toggle[RepU]=1;
			Val[RepU]=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=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;
		//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<=m+n+1;i++){
		CurRep[i]=i;
	}		
	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 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 12636 KB Output is correct
3 Correct 2 ms 12636 KB Output is correct
4 Correct 2 ms 12636 KB Output is correct
5 Correct 2 ms 12892 KB Output is correct
6 Correct 2 ms 12892 KB Output is correct
7 Correct 2 ms 12892 KB Output is correct
8 Correct 2 ms 12892 KB Output is correct
9 Correct 87 ms 44148 KB Output is correct
10 Correct 91 ms 53788 KB Output is correct
11 Correct 91 ms 54304 KB Output is correct
12 Correct 98 ms 54820 KB Output is correct
13 Correct 102 ms 56484 KB Output is correct
14 Correct 83 ms 43804 KB Output is correct
15 Correct 208 ms 55004 KB Output is correct
16 Correct 175 ms 52644 KB Output is correct
17 Correct 194 ms 56452 KB Output is correct
18 Correct 232 ms 57152 KB Output is correct
19 Incorrect 75 ms 25412 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 12636 KB Output is correct
3 Incorrect 191 ms 57192 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 12636 KB Output is correct
3 Correct 2 ms 12636 KB Output is correct
4 Correct 2 ms 12636 KB Output is correct
5 Correct 2 ms 12892 KB Output is correct
6 Correct 2 ms 12892 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 12636 KB Output is correct
3 Correct 2 ms 12636 KB Output is correct
4 Correct 2 ms 12636 KB Output is correct
5 Correct 2 ms 12892 KB Output is correct
6 Correct 2 ms 12892 KB Output is correct
7 Correct 2 ms 12892 KB Output is correct
8 Correct 2 ms 12892 KB Output is correct
9 Correct 87 ms 44148 KB Output is correct
10 Correct 91 ms 53788 KB Output is correct
11 Correct 91 ms 54304 KB Output is correct
12 Correct 98 ms 54820 KB Output is correct
13 Correct 102 ms 56484 KB Output is correct
14 Correct 83 ms 43804 KB Output is correct
15 Correct 208 ms 55004 KB Output is correct
16 Correct 175 ms 52644 KB Output is correct
17 Correct 194 ms 56452 KB Output is correct
18 Correct 232 ms 57152 KB Output is correct
19 Incorrect 191 ms 57192 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 -