Submission #1081490

#	Time	Username	Problem	Language	Result	Execution time	Memory
1081490		LCJLY	The Ties That Guide Us (CEOI23_incursion)	C++17	12 / 100	3015 ms	11676 KiB

incursion

#include "incursion.h"
#include <bits/stdc++.h>
//#include "sample_grader.cpp"
using namespace std;

//#define int long long 
//#define ld long double
#define show(x,y) cerr << y << " " << #x << endl;
#define show2(x,y,i,j) cerr << y << " " << #x << "  " << j << " " << #i << endl;
#define show3(x,y,i,j,p,q) cerr << y << " " << #x << "  " << j << " " << #i << "  " << q << " " << #p << endl;
#define show4(x,y) for(auto it:y) cerr << it << " "; cout << #x << endl;
typedef pair<int,int>pii;
typedef pair<pii,int>pi2;

int n;
vector<int>adj[45005];
int pp[45005];
int sz[45005];

void dfs(int index, int par){
	sz[index]=1;
	for(auto it:adj[index]){
		if(it==par) continue;
		pp[it]=index;
		dfs(it,index); 
		sz[index]+=sz[it];
	}
}

vector<int>mark(vector<pair<int, int>> F, int safe){
	n=F.size()+1;
	for(int x=0;x<n-1;x++){
		adj[F[x].first].push_back(F[x].second);
		adj[F[x].second].push_back(F[x].first);
	}
	
	int rt=0;
	for(int x=1;x<=n;x++){
		if(adj[x].size()==2){
			dfs(x,-1);
			rt=x;
		}
	}
	//show(rt,rt);
	
	vector<int>ans(n,0);
	int cur=safe;
	int take=-1;
	while(cur){
		ans[cur-1]=1;
		if(take==-1){
			ans[cur-1]=1;
			if(cur==rt) break;
			take=cur;
			cur=pp[cur];
		}
		else{
			//show2(cur,cur,take,take);
			int nxt=sz[cur]-sz[take]-1;	
			//show2(sz[take],sz[take],nxt,nxt);
			if(sz[take]<nxt){
				ans[cur-1]=1;
			}
			else ans[cur-1]=2;
			if(cur==rt) break;
			take=cur;
			cur=pp[cur];
		}
	}
	return ans;
}


//visit()
void locate(vector<pair<int, int>> F, int curr, int t){
	n=F.size()+1;
	for(int x=0;x<=n;x++){
		adj[x].clear();
	}
	for(int x=0;x<n-1;x++){
		adj[F[x].first].push_back(F[x].second);
		adj[F[x].second].push_back(F[x].first);
	}
	memset(pp,0,sizeof(pp));
	memset(sz,0,sizeof(sz));
	
	for(int x=1;x<=n;x++){
		if(adj[x].size()==2){
			dfs(x,-1);
		}
	}
	
	bool done[n+5];
	memset(done,0,sizeof(done));
	
	while(1){
		//show2(curr,curr,t,t);
		done[curr]=true;
		if(t==0){
			//go up
			done[curr]=true;
			t=visit(pp[curr]);
			curr=pp[curr];
		}
		else if(t==1){
			//go small
			bool amos=false;
			pii mini={1e9,0};
			for(auto it:adj[curr]){
				if(it==pp[curr]) continue;
				if(done[it]) continue;
				//show(it,it);
				mini=min(mini,{sz[it],it});
				amos=true;
			}
			
			//show2(mini.first,mini.first,mini.second,mini.second);
			if(!amos||done[mini.second]) return;
			t=visit(mini.second);
			curr=mini.second;
		}
		else{
			//go big
			pii maxi={-1e9,0};
			bool amos=false;
			for(auto it:adj[curr]){
				if(it==pp[curr]) continue;
				if(done[it]) continue;
				maxi=max(maxi,{sz[it],it});
				amos=true;
			}
			if(!amos||done[maxi.second]) return;
			t=visit(maxi.second);
			curr=maxi.second;
		}
		//show(curr,curr);
	}
}

Compilation message (stderr)

interface.cpp: In function 'int main()':
interface.cpp:44:55: warning: comparison of integer expressions of different signedness: 'size_t' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   44 |     if(fread(T.data(), sizeof(int), 2 * N - 2, stdin) != 2 * N - 2) exit(0);
      |        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~
interface.cpp:50:33: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   50 |         int l = (numbers.size() == N ? N : 0);
      |                  ~~~~~~~~~~~~~~~^~~~

• Subtask 0: 0 / 0
• Subtask 1: 0 / 30
• Subtask 2: 12 / 30
• Subtask 3: 0 / 40