Submission #1268432


Source Code Expand

#include "bits/stdc++.h"
#define MAXN 150009
#define INF 1000000007
#define mp(x,y) make_pair(x,y)
#define all(v) v.begin(),v.end()
#define pb(x) push_back(x)
#define wr cout<<"----------------"<<endl;
#define ppb() pop_back()
#define tr(ii,c) for(typeof((c).begin()) ii=(c).begin();ii!=(c).end();ii++)
#define ff first
#define ss second
#define my_little_dodge 46
using namespace std;

typedef long long ll;
typedef pair<int,int> PII;
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
vector<int>adj[MAXN];
double ans[MAXN],suf[MAXN],pre[MAXN],res[MAXN];
double dfs(int nd,int pr){
	if(~pr and adj[nd].size()==1)
		return 0.0;
	for(int i=0;i<int(adj[nd].size());i++){
		int to=adj[nd][i];
		if(to==pr)
			continue;
		ans[nd]+=dfs(to,nd);	
	}
	if(~pr)
		ans[nd]=ans[nd]/double(adj[nd].size()-1)+1.0;
	else	
		ans[nd]=ans[nd]/double(adj[nd].size())+1.0;
	return ans[nd];	
}
void dfs1(int nd,int pr,double par){
	res[nd]=par;
	for(int i=0;i<int(adj[nd].size());i++){
		int to=adj[nd][i];
		if(to==pr)
			continue;
		res[nd]+=ans[to];	
	}
	res[nd]=res[nd]/double(adj[nd].size())+1;
	if(adj[nd].size()==1){
		if(pr==-1)
			dfs1(adj[nd][0],nd,0);
		return;
	}
	double sum=0;
	for(int i=0;i<int(adj[nd].size());i++){
		int to=adj[nd][i];
		if(to==pr)
			continue;
		pre[to]=sum;
		sum+=ans[to];
	}sum=0;
	for(int i=int(adj[nd].size()-1);i>=0;i--){
		int to=adj[nd][i];
		if(to==pr)
			continue;
		suf[to]=sum;
		sum+=ans[to];
	}
	for(int i=0;i<int(adj[nd].size());i++){
		int to=adj[nd][i];
		if(to==pr)	
			continue;
		dfs1(to,nd,(par+suf[to]+pre[to])/double(adj[nd].size()-1)+1.0);	
	}
}
int main(){
	//~ #ifndef ONLINE_JUDGE
    //~ freopen("file.in", "r", stdin);
	//~ #endif	
	int n;
	scanf("%d",&n);
	for(int i=1;i<n;i++){
		int u,v;
		scanf("%d%d",&u,&v);
		adj[u].pb(v);
		adj[v].pb(u);
	}
	dfs(1,-1);
	dfs1(1,-1,0);
	for(int i=1;i<=n;i++)
		printf("%.12lf\n",res[i]);	
	return 0;
}

Submission Info

Submission Time
Task D - Driving on a Tree
User KerimK
Language C++14 (GCC 5.4.1)
Score 800
Code Size 2064 Byte
Status AC
Exec Time 119 ms
Memory 21120 KB

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:77:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
                ^
./Main.cpp:80:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&u,&v);
                      ^

Judge Result

Set Name Subtask1 Subtask2 Subtask3
Score / Max Score 190 / 190 220 / 220 390 / 390
Status
AC × 3
AC × 2
AC × 8
Set Name Test Cases
Subtask1 sub1_in1.txt, sub1_in2.txt, sub1_in3.txt
Subtask2 sub2_in1.txt, sub2_in2.txt
Subtask3 sub1_in1.txt, sub1_in2.txt, sub1_in3.txt, sub2_in1.txt, sub2_in2.txt, sub3_in1.txt, sub3_in2.txt, sub3_in3.txt
Case Name Status Exec Time Memory
sub1_in1.txt AC 3 ms 6400 KB
sub1_in2.txt AC 4 ms 6528 KB
sub1_in3.txt AC 119 ms 18688 KB
sub2_in1.txt AC 3 ms 6400 KB
sub2_in2.txt AC 3 ms 6400 KB
sub3_in1.txt AC 116 ms 15360 KB
sub3_in2.txt AC 84 ms 15860 KB
sub3_in3.txt AC 103 ms 21120 KB