#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ld long double
#define pb push_back //emplace_back
#define pp pop_back
#define pii pair<ll, ll> //pair<int, int>
#define all(x) (x).begin(),(x).end()
#define mp(a,b) make_pair(a , b)
#define lb lower_bound
#define ub upper_bound
#define sz(x) (ll)(x).size()
#define F first
#define S second
#define bg(x) (x).begin()
#define For(x, n) for(int (x) = 0 ; (x) < (n) ; (x)++)
#define debug(x) cout << #x << " : " << x << endl
#define endl '\n'
#define arr(x) array<int , (x)>
#define yes cout << "impossible\n"
#define no cout << "NO\n"
#define FAST ios_base::sync_with_stdio(0);cin.tie(0);
#define INF 1000000000000000000
ll Sum(ll a , ll b , ll MOD)
{
a %= MOD;
b %= MOD;
a += b;
return a % MOD;
}
ll Mul(ll a , ll b , ll MOD)
{
a %= MOD;
b %= MOD;
a *= b;
return a % MOD;
}
ll Pow(ll a , ll b , ll MOD)
{
ll res = 1;
while(b)
{
if((b & 1))res = Mul(res , a , MOD);
a = Mul(a , a , MOD);
b >>= 1;
}
return res;
}
ll Min(ll a , ll b)
{
if(a > b)return b;
return a;
}
ll Max(ll a , ll b)
{
if(a > b)return a;
return b;
}
ll Ceil(ll a , ll b)
{
if(a % b)return (a/b)+1;
return a/b;
}
/////////////////////
//VALS
ll n;
const ll maxn = 1e5+1e3;
vector<ll> adj[maxn];
ll dp[maxn][2][2];
ll a[maxn];
/////////////////////
//FUNCTIONS
void dfs(ll i,ll par = -1)
{
dp[i][0][a[i]] = 0;
dp[i][0][a[i] ^ 1] = INF;
dp[i][1][a[i] ^ 1] = 1;
dp[i][1][a[i]] = INF;
for (int j : adj[i])
if (j != par)
{
dfs(j, i);
for (int s = 0; s < 2; s++)
{
ll dp0 = dp[i][s][0], dp1 = dp[i][s][1];
dp[i][s][0] = Min(INF, Min(dp0 + dp[j][0][s], dp1 + dp[j][1][s]));
dp[i][s][1] = Min(INF, Min(dp0 + dp[j][1][s], dp1 + dp[j][0][s]));
}
}
}
/////////////////////
//SOLVE
void solve()
{
cin >> n;
For(i,n-1)
{
ll u, v;
cin >> u >> v;
u--;
v--;
adj[u].pb(v);
adj[v].pb(u);
}
For(i,n)cin >> a[i];
dfs(0,0);
if(dp[0][0][0] == dp[0][1][0] and dp[0][1][0] == INF)no;
else
cout << Min(dp[0][0][0], dp[0][1][0]) << endl;
}
/////////////////////
//MAIN
int main()
{
FAST;
ll t = 1;
// cin >> t;
while(t--)
{
solve();
}
}
/////////////////////
/*
ZZZZZZZ A M M IIIIIII N N
Z A A M M M M I NN N
Z A A M M M M I N N N
Z AAAAAAA M M M I N N N
Z A A M M I N N N
Z A A M M I N NN
ZZZZZZZ A A M M IIIIIII N N TREE
*/
Compilation message
xanadu.cpp: In function 'void solve()':
xanadu.cpp:20:27: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
20 | #define For(x, n) for(int (x) = 0 ; (x) < (n) ; (x)++)
| ^
xanadu.cpp:112:2: note: in expansion of macro 'For'
112 | For(i,n-1)
| ^~~
xanadu.cpp:20:27: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
20 | #define For(x, n) for(int (x) = 0 ; (x) < (n) ; (x)++)
| ^
xanadu.cpp:122:2: note: in expansion of macro 'For'
122 | For(i,n)cin >> a[i];
| ^~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
6488 KB |
Output is correct |
2 |
Correct |
2 ms |
6492 KB |
Output is correct |
3 |
Correct |
2 ms |
6744 KB |
Output is correct |
4 |
Correct |
3 ms |
6488 KB |
Output is correct |
5 |
Incorrect |
2 ms |
6492 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
6488 KB |
Output is correct |
2 |
Correct |
2 ms |
6492 KB |
Output is correct |
3 |
Correct |
2 ms |
6744 KB |
Output is correct |
4 |
Correct |
3 ms |
6488 KB |
Output is correct |
5 |
Incorrect |
2 ms |
6492 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
41 ms |
17488 KB |
Output is correct |
2 |
Incorrect |
49 ms |
17280 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
41 ms |
17472 KB |
Output is correct |
2 |
Incorrect |
39 ms |
17488 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
6488 KB |
Output is correct |
2 |
Correct |
2 ms |
6492 KB |
Output is correct |
3 |
Correct |
2 ms |
6744 KB |
Output is correct |
4 |
Correct |
3 ms |
6488 KB |
Output is correct |
5 |
Incorrect |
2 ms |
6492 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |