Submission #391359

#	Time	Username	Problem	Language	Result	Execution time	Memory
391359		lukameladze	Power Plant (JOI20_power)	C++14	100 / 100	297 ms	35132 KiB

power

# include <bits/stdc++.h>
#define f first
#define s second
#define pb push_back
using namespace std;
const int N=3e5+5;
long long par[N],dp[N],dp1[N],n,a,b,bb,ans;
vector <long long> v[N];
string s;
void dfs (int a, int p) {
     int ff=0;
     par[a]=p;
     for (int i=0; i<v[a].size(); i++) {
          if (v[a][i]!=p) {
               dfs(v[a][i],a);
               dp[a]+=dp[v[a][i]];
               if (s[a]=='1' && !ff) dp[a]--, ff=1;
               dp1[a]+=dp1[v[a][i]];
          }
     }
     dp1[a]++;
    if (s[a]=='1') dp[a]=max(1LL, dp[a]);
    if (s[a]=='0') dp[a]=max(0LL,dp[a]);
}
int main() {
     cin>>n;
     for (int i=1; i<=n-1; i++) {
          cin>>a>>b;
          v[a].pb(b);
          v[b].pb(a);
     }
     cin>>s;
     s="@"+s;
     dfs(1,0);
     for (int i=1; i<=n; i++) {
          if (par[i] && s[par[i]]=='1') bb=1; else bb=0;
          ans=max(ans,dp[i]+bb);
     }
     cout<<ans<<endl;
}

Compilation message (stderr)

power.cpp: In function 'void dfs(int, int)':
power.cpp:13:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |      for (int i=0; i<v[a].size(); i++) {
      |                    ~^~~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 41 / 41
• Subtask 3: 53 / 53