#include<bits/stdc++.h> using namespace std; #define ll long long #define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; i++) #define FORD(i, b, a) for (int i = (b), _a = (a); i >= _a; i--) #define pa pair<ll, ll> #define fi first #define se second #define bit(mask, j) ((mask >> j) & 1) const ll mod = 1e9 + 7; const ll INF = 1e18; //-------------------------------------------------------------------- const ll N = 2e5 + 10; vector<ll> g[N]; ll dp[N][3]; ll c[N]; ll n; void dfs(ll u, ll p) { ll mn = 0; ll sum = 0; dp[u][1] = c[u]; for(auto v : g[u]) { if(v == p) continue; dfs(v, u); dp[u][2] = max(dp[u][2], dp[v][2]); if(c[u]) dp[u][2] = max(dp[u][2], dp[v][1] + 1); sum += dp[v][1]; } dp[u][1] = max(dp[u][1], sum - c[u]); } void hbmt() { cin >> n; FOR(i, 1, n - 1) { ll u, v; cin >> u >> v; g[u].push_back(v); g[v].push_back(u); } ll cnt = 0; FOR(i, 1, n) { char x; cin >> x; c[i] = x - '0'; cnt += c[i]; } if(cnt == 0) { cout << 0; return; } ll ans = 0; ans = min(cnt, 2LL); dfs(1, 0); ans = max({ans, dp[1][2], dp[1][1]}); cout << ans; } int main() { ios_base::sync_with_stdio(0); cin.tie(0);cout.tie(0); #define NAME "hbmt" if(fopen(NAME".inp", "r")) { freopen(NAME".inp", "r", stdin); freopen(NAME".out", "w", stdout); } //int t;cin>>t;while(t--) hbmt(); return 0; }

power.cpp: In function 'int main()':
power.cpp:68:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   68 |                 freopen(NAME".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
power.cpp:69:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |                 freopen(NAME".out", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~