Submission #1372899


Source Code Expand

#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <string>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <climits>
#include <cstring>
#include <cstdlib>
#include <fstream>
#include <numeric>
#include <sstream>
#include <cassert>
#include <iomanip>
#include <iostream>
#include <algorithm>
#include <unordered_set>
#include <unordered_map>

using namespace std;

#define f first
#define s second
#define pb push_back
#define pp pop_back
#define mp make_pair
#define ll long long
#define ld double
#define ull unsigned long long
#define PI pair < int, int > 

const int N = 5e5 + 123;
const int M = 123;
const ld Pi = acos(-1);
const ll Inf = 1e18;
const int inf = 1e9;
const int mod = 1e9 + 7;
const int Sz = 501;
const int MOD = 1e9 + 7;

void add(int &a, int b) {
  a += b;
  if (a >= mod) a -= mod;
}
int mult(int a, int b) {
  return 1ll * a * b % mod;
}
int sum(int a, int b) {
  add(a, b);
  return a;
}

int n, a[N];
vector < int > g[N];

ll dfs(int v, int p = -1) {
  vector < ll > now;
  ll x = a[v];
  ll y = 0;
  for (auto to : g[v]) {
    if (to != p) {
      ll tmp = dfs(to, v);
      y += tmp;
      now.pb(tmp);
    }
  }
  if (now.size() == 0) return x;
  if (x > y) {
    cout << "NO\n";
    exit(0);
  }
  ll z = y - x;
  multiset < ll > st;
  for (auto i : now) st.insert(i);
  while(z > 0) {
    if (now.size() < 2) break;
    ll mn = *st.begin();
    st.erase(st.find(mn));
    ll mx = *st.rbegin();
    st.erase(st.find(mx));
    ll cur = min(z, mn);
    mn -= cur;
    mx -= cur;
    x -= cur;
    y -= cur;
    z -= cur;
    if (mn > 0) st.insert(mn);
    if (mx > 0) st.insert(mx); 
  }
  if (z > 0) {
    cout << "NO\n";
    exit(0);
  }
  return x;
}
void solve() { 
  scanf("%d", &n);
  for (int i = 1;i <= n;i++) scanf("%d", &a[i]);
  for (int i = 1, u, v;i < n;i++) {
    scanf("%d%d", &u, &v);
    g[u].pb(v);
    g[v].pb(u);
  }
  if (n == 2) {
    if (a[1] != a[2]) cout << "NO\n";
    else cout << "YES\n";
    return;
  }
  int rt = 1;
  while(g[rt].size() == 1) rt++;
  assert(rt <= n && g[rt].size() > 1);
  if (dfs(rt) == 0) cout << "YES\n";
  else cout << "NO\n";
}

int main() {
  #ifdef wws
   freopen("in", "r", stdin);
   // freopen("in", "w", stdout);
  #endif 
//  ios_base::sync_with_stdio(0);
  int tt = 1; 
  while(tt--) solve();
  return 0;
}

Submission Info

Submission Time
Task C - Cleaning
User SmallBoy
Language C++14 (GCC 5.4.1)
Score 0
Code Size 2547 Byte
Status RE
Exec Time 2104 ms
Memory 29056 KB

Compile Error

./Main.cpp: In function ‘void solve()’:
./Main.cpp:104:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &n);
                  ^
./Main.cpp:105:48: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   for (int i = 1;i <= n;i++) scanf("%d", &a[i]);
                                                ^
./Main.cpp:107:26: 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 Sample All
Score / Max Score 0 / 0 0 / 700
Status
AC × 2
RE × 1
AC × 27
TLE × 2
RE × 22
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 63 ms 15744 KB
in10.txt AC 60 ms 15744 KB
in11.txt AC 71 ms 26496 KB
in12.txt AC 68 ms 26496 KB
in13.txt AC 66 ms 29056 KB
in14.txt AC 66 ms 27136 KB
in15.txt RE 101 ms 12544 KB
in16.txt RE 104 ms 12544 KB
in17.txt AC 5 ms 12544 KB
in18.txt AC 5 ms 12544 KB
in19.txt RE 149 ms 15744 KB
in2.txt AC 62 ms 15744 KB
in20.txt RE 141 ms 15744 KB
in21.txt RE 141 ms 15872 KB
in22.txt RE 151 ms 15744 KB
in23.txt AC 56 ms 15744 KB
in24.txt AC 52 ms 15744 KB
in25.txt RE 103 ms 12544 KB
in26.txt AC 49 ms 15744 KB
in27.txt AC 50 ms 15744 KB
in28.txt TLE 2103 ms 12544 KB
in29.txt RE 138 ms 15744 KB
in3.txt RE 153 ms 15744 KB
in30.txt AC 5 ms 12544 KB
in31.txt AC 57 ms 15744 KB
in32.txt AC 51 ms 15744 KB
in33.txt RE 154 ms 15744 KB
in34.txt RE 154 ms 15744 KB
in35.txt AC 61 ms 15744 KB
in36.txt AC 60 ms 15744 KB
in37.txt RE 103 ms 12544 KB
in38.txt RE 150 ms 15744 KB
in39.txt RE 151 ms 15744 KB
in4.txt RE 164 ms 15744 KB
in40.txt RE 151 ms 15744 KB
in41.txt TLE 2104 ms 15744 KB
in42.txt RE 154 ms 15744 KB
in43.txt AC 55 ms 15744 KB
in44.txt RE 156 ms 15744 KB
in45.txt RE 154 ms 15744 KB
in5.txt AC 63 ms 15744 KB
in6.txt AC 60 ms 15744 KB
in7.txt RE 148 ms 15360 KB
in8.txt AC 18 ms 13312 KB
in9.txt AC 61 ms 15872 KB
sample1.txt AC 5 ms 12544 KB
sample2.txt AC 5 ms 12544 KB
sample3.txt RE 102 ms 12544 KB