Submission #1480615


Source Code Expand

#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define rep(i,n) for(ll i=0;i<(ll)(n);i++)
#define all(a) (a).begin(),(a).end()
#define pb emplace_back
#define INF (1e9+1)

vector<int> G[100000];
vector<int> a(100000);
vector<int> deg;

int dfs(int cur, int prev){
    if(deg[cur]==1)return a[cur];
    ll sigma = 0;
    int maxC = 0;
    for(auto e:G[cur]){
        if(e==prev)continue;
        int res = dfs(e,cur);
        maxC = max(maxC,res);
        sigma+=res;
    }
    
    int t = 2*a[cur] - sigma;
    if( t<0 || t>a[cur] || (sigma-t)%2==1 || sigma-t > 2*min(sigma-maxC,sigma/2) )throw -1;
    
    return t;
}

int main(){
    int n;
    cin>>n;
    rep(i,n)cin>>a[i];
    
    deg.resize(n,0);
    rep(i,n-1){
        int s,t;
        cin>>s>>t;
        s--,t--;
        deg[s]++;
        deg[t]++;
        G[s].pb(t);
        G[t].pb(s);
    }
    
    int root = 0;
    while(deg[root]==1)root++;
    
    int res;
    try{
        res = dfs(root,-1);
    }catch(int e){
        cout<<"NO"<<endl;
        return 0;
    }
    if(res==0){
        cout<<"YES"<<endl;
    }else{
        cout<<"NO"<<endl;
    }
}

Submission Info

Submission Time
Task C - Cleaning
User Yazaten
Language C++14 (GCC 5.4.1)
Score 0
Code Size 1231 Byte
Status WA
Exec Time 115 ms
Memory 13184 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 0 / 700
Status
AC × 3
AC × 50
WA × 1
Set Name Test Cases
Sample sample1.txt, sample2.txt, sample3.txt
All sample1.txt, sample2.txt, sample3.txt, in1.txt, in10.txt, in11.txt, in12.txt, in13.txt, in14.txt, in15.txt, in16.txt, in17.txt, in18.txt, in19.txt, in2.txt, in20.txt, in21.txt, in22.txt, in23.txt, in24.txt, in25.txt, in26.txt, in27.txt, in28.txt, in29.txt, in3.txt, in30.txt, in31.txt, in32.txt, in33.txt, in34.txt, in35.txt, in36.txt, in37.txt, in38.txt, in39.txt, in4.txt, in40.txt, in41.txt, in42.txt, in43.txt, in44.txt, in45.txt, in5.txt, in6.txt, in7.txt, in8.txt, in9.txt, sample1.txt, sample2.txt, sample3.txt
Case Name Status Exec Time Memory
in1.txt AC 103 ms 6656 KB
in10.txt AC 104 ms 6656 KB
in11.txt AC 112 ms 11904 KB
in12.txt AC 115 ms 11904 KB
in13.txt AC 92 ms 13184 KB
in14.txt AC 92 ms 12288 KB
in15.txt AC 2 ms 2944 KB
in16.txt AC 2 ms 2944 KB
in17.txt AC 2 ms 2944 KB
in18.txt WA 2 ms 2944 KB
in19.txt AC 101 ms 6656 KB
in2.txt AC 104 ms 6656 KB
in20.txt AC 102 ms 6656 KB
in21.txt AC 102 ms 6656 KB
in22.txt AC 103 ms 6656 KB
in23.txt AC 102 ms 6656 KB
in24.txt AC 101 ms 6656 KB
in25.txt AC 3 ms 2944 KB
in26.txt AC 111 ms 6656 KB
in27.txt AC 111 ms 6656 KB
in28.txt AC 2 ms 2944 KB
in29.txt AC 88 ms 6656 KB
in3.txt AC 104 ms 6656 KB
in30.txt AC 2 ms 2944 KB
in31.txt AC 103 ms 6656 KB
in32.txt AC 102 ms 6656 KB
in33.txt AC 105 ms 6656 KB
in34.txt AC 104 ms 6656 KB
in35.txt AC 103 ms 6656 KB
in36.txt AC 105 ms 6656 KB
in37.txt AC 3 ms 3072 KB
in38.txt AC 102 ms 6656 KB
in39.txt AC 103 ms 6656 KB
in4.txt AC 103 ms 6656 KB
in40.txt AC 102 ms 6656 KB
in41.txt AC 100 ms 6656 KB
in42.txt AC 103 ms 6656 KB
in43.txt AC 102 ms 6656 KB
in44.txt AC 104 ms 6656 KB
in45.txt AC 104 ms 6656 KB
in5.txt AC 104 ms 6656 KB
in6.txt AC 105 ms 6656 KB
in7.txt AC 92 ms 6272 KB
in8.txt AC 25 ms 3840 KB
in9.txt AC 104 ms 6656 KB
sample1.txt AC 2 ms 2944 KB
sample2.txt AC 2 ms 2944 KB
sample3.txt AC 2 ms 2944 KB