oj.uz

Submission #291750

# Submission time Handle Problem Language Result Execution time Memory
291750 2020-09-05T18:18:15 Z Marlov Mag (COCI16_mag) C++14
72 / 120
 535 ms 170568 KB 
/*
Code by @marlov       
*/
#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
#include <vector>
#include <string>
#include <cmath>
#include <algorithm>
#include <iomanip>
#include <utility>
#include <set>
#include <unordered_set>
#include <map>
#include <unordered_map>
#include <stack>
#include <queue>
#include <iterator>
using namespace std;
typedef long long ll;
typedef pair<int,int> pi;

#define maxN 1000005
#define INF 2000000000

int N;
vector<int> adj[maxN];
int magic[maxN];
int dp1[maxN];
int f1[maxN];
int dp2[maxN];
int f2[maxN];
int tmv=INF;
int top=1;
int bottom=1;

void dfsbu(int n,int p){

	for(int i:adj[n]) if(i!=p){
		dfsbu(i,n);
	}

	if(magic[n]>2) return;

	for(int i:adj[n]) if(i!=p){
		if(magic[i]==1){
			if(dp1[i]>=dp1[n]){
				dp2[n]=dp1[n];
				dp1[n]=dp1[i]+1;
				f1[n]=i;
			}else if(dp2[i]>=dp2[n]){
				dp2[n]=dp2[i]+1;
				f2[n]=i;
			}
		}
	}
}

void dfsud(int n,int p){
	
	if(magic[n]<3&&n!=0&&magic[p]==1){
		if(dp1[p]>=dp1[n]&&f1[p]!=n){
			dp2[n]=dp1[n];
			dp1[n]=dp1[p]+1;
			f1[n]=p;
		}else if(dp2[p]>=dp2[n]&&f2[p]!=n){
			dp2[n]=dp2[p]+1;
			f2[n]=p;
		}
	}
	for(int i:adj[n]) if(i!=p){
		dfsud(i,n);
	}
}
int main() {
	ios_base::sync_with_stdio(0); cin.tie(0);
	cin>>N;
	int u,v;
	for(int i=0;i<N-1;i++){
		cin>>u>>v;
		u--;v--;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	for(int i=0;i<N;i++){
		cin>>magic[i];
		tmv=min(tmv,magic[i]);
		f1[i]=-1;
		f2[i]=-1;
		dp1[i]=0;
		dp2[i]=0;
		//if(magic[i]==1) dp1[i]=1;
	}
	if(tmv>1){
		cout<<tmv<<"/"<<1<<'\n';
		return 0;
	}
	dfsbu(0,-1);
	dfsud(0,-1);
    for(int i=0;i<N;i++){
		if(magic[i]>2) continue;
		if(top*(dp1[i]+dp2[i]+1)>bottom*magic[i]){
			top=magic[i];
			bottom=(dp1[i]+dp2[i]+1);
		}
	}
	if(top==2&&bottom%2==0){
		cout<<top/2<<"/"<<bottom/2<<'\n';
	}else{
		cout<<top<<"/"<<bottom<<'\n';
	}
	return 0;
}

/* stuff you should look for
	* int overflow, array bounds
	* special cases (n=1,n=0?)
	* do smth instead of nothing and stay organized
*/

Subtask #1
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 23936 KB Output is correct
2 Correct 15 ms 23936 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 23936 KB Output is correct
2 Correct 16 ms 23936 KB Output is correct

Subtask #3
0 / 12.0

# Verdict Execution time Memory Grader output
1 Incorrect 364 ms 95992 KB Output isn't correct

Subtask #4
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 23808 KB Output is correct
2 Correct 481 ms 167276 KB Output is correct

Subtask #5
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 479 ms 149780 KB Output is correct

Subtask #6
0 / 12.0

# Verdict Execution time Memory Grader output
1 Incorrect 399 ms 74620 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #7
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 384 ms 75492 KB Output is correct
2 Correct 93 ms 29304 KB Output is correct
3 Correct 535 ms 170568 KB Output is correct

Subtask #8
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 93 ms 29176 KB Output is correct
2 Incorrect 400 ms 75440 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #9
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 360 ms 71428 KB Output is correct
2 Incorrect 417 ms 73948 KB Output isn't correct

Subtask #10
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 406 ms 75256 KB Output is correct
2 Correct 394 ms 50076 KB Output is correct