Submission #1227660


Source Code Expand

#include <bits/stdc++.h>
using namespace std;
/*{{{*/  //template
#define REP(i,n) for(int i=0;i<n;i++)
#define rep(i,n) for(int i=0;i<n;i++)
#define INF 1<<29
#define LINF LLONG_MAX/3
#define MP make_pair
#define PB push_back
#define pb push_back
#define EB emplace_back
#define ALL(v) (v).begin(),(v).end()
#define all(v) ALL(v)
#define sz(x) (int)(x).size()
#define debug(x) cerr<<#x<<":"<<x<<endl
#define debug2(x,y) cerr<<#x<<","<<#y":"<<x<<","<<y<<endl
//struct fin{ fin(){ cin.tie(0); ios::sync_with_stdio(false); } } fin_;
struct Double{ double d; explicit Double(double x) : d(x){} };
ostream& operator<<(ostream& os,const Double x){ os << fixed << setprecision(20) << x.d; return os; }
template<typename T> ostream& operator<<(ostream& os,const vector<T>& vec){ os << "["; for(const auto& v : vec){ os << v << ","; } os << "]"; return os; }
template<typename T,typename U> ostream& operator<<(ostream& os,const pair<T,U>& p){ os << "(" << p.first << ","<< p.second <<")"; return os; }
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
ll gcd(ll a,ll b){ if(b==0) return a; else return gcd(b,a%b); }
constexpr double eps = 1e-14; 
constexpr ll mod = 1e9+7;
const int dx[]={1,0,-1,0} ,dy[] = {0,1,0,-1};
/*}}}*/

constexpr ll MN = 100011;
ll N;

array<ll,MN> A;
array<vector<ll>,MN> g;
bool ans=true;

ll dfs(ll c,ll p){
    // leaf
    if(sz(g[c])==1) return A[c];
    // not leaf
    vector<ll> ch;
    for(auto v:g[c]) if(v!=p){
        ch.pb(dfs(v,c));
    }
    ll mx = *max_element(all(ch));
    ll sum = accumulate(all(ch),0);

    ll np = 2*A[c]-sum;  // connect for the direction of parent
    ll cp = (sum-np)/2;

    if(np<0 or (sum-np)%2==1){ ans=false; }
    if(sum-mx<cp){ ans=false; }
//    cout << "dfs(" << c << "," << p << ") = " << np << endl;
    return np;
}

int main(){
    cin >> N;
    rep(i,N) cin>>A[i];
    rep(i,N-1){
        ll a,b;cin>>a>>b;a--;b--;
        g[a].pb(b);
        g[b].pb(a);
    }

    if(N==2){
        cout << (A[0]==A[1] ? "YES" : "NO") << endl;
        return 0;
    }

    ll tmp;
    for(int i=0;i<N;i++) if(sz(g[i])>1){
//        cout << "root:" << i << endl;
        tmp = dfs(i,-1);
        break;
    }
    if(!ans){
        cout << "NO" << endl;
        return 0;
    }
    if(tmp==0) cout << "YES" << endl;
    else cout << "NO" << endl;
}

Submission Info

Submission Time
Task C - Cleaning
User chakku000
Language C++14 (GCC 5.4.1)
Score 0
Code Size 2471 Byte
Status WA
Exec Time 123 ms
Memory 14464 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 0 / 700
Status
AC × 3
AC × 47
WA × 4
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 108 ms 7168 KB
in10.txt AC 107 ms 7168 KB
in11.txt AC 116 ms 13056 KB
in12.txt AC 119 ms 13056 KB
in13.txt AC 98 ms 14464 KB
in14.txt AC 96 ms 13440 KB
in15.txt AC 2 ms 2560 KB
in16.txt AC 2 ms 2560 KB
in17.txt AC 2 ms 2560 KB
in18.txt AC 2 ms 2560 KB
in19.txt AC 107 ms 7040 KB
in2.txt AC 108 ms 7168 KB
in20.txt AC 109 ms 7040 KB
in21.txt AC 110 ms 7040 KB
in22.txt AC 112 ms 7168 KB
in23.txt WA 123 ms 7040 KB
in24.txt AC 109 ms 7168 KB
in25.txt AC 2 ms 2560 KB
in26.txt AC 120 ms 7168 KB
in27.txt AC 120 ms 7168 KB
in28.txt AC 2 ms 2560 KB
in29.txt AC 98 ms 7040 KB
in3.txt AC 107 ms 7168 KB
in30.txt WA 2 ms 2560 KB
in31.txt WA 111 ms 7168 KB
in32.txt WA 111 ms 7168 KB
in33.txt AC 107 ms 7168 KB
in34.txt AC 111 ms 7168 KB
in35.txt AC 108 ms 7168 KB
in36.txt AC 110 ms 7168 KB
in37.txt AC 3 ms 2688 KB
in38.txt AC 107 ms 7168 KB
in39.txt AC 108 ms 7168 KB
in4.txt AC 107 ms 7040 KB
in40.txt AC 109 ms 7168 KB
in41.txt AC 109 ms 7168 KB
in42.txt AC 108 ms 7168 KB
in43.txt AC 108 ms 7168 KB
in44.txt AC 110 ms 7168 KB
in45.txt AC 107 ms 7168 KB
in5.txt AC 107 ms 7168 KB
in6.txt AC 108 ms 7040 KB
in7.txt AC 96 ms 6656 KB
in8.txt AC 26 ms 3712 KB
in9.txt AC 118 ms 7168 KB
sample1.txt AC 2 ms 2560 KB
sample2.txt AC 2 ms 2560 KB
sample3.txt AC 2 ms 2560 KB