Submission #629362

#	Time	Username	Problem	Language	Result	Execution time	Memory
629362		urosk	Power Plant (JOI20_power)	C++14	100 / 100	142 ms	35260 KiB

power

#define here cerr<<"===========================================\n"
#define dbg(x) cerr<<#x<<": "<<x<<endl;
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#define ld double
#define ll long long
#define llinf 100000000000000000LL // 10^17
#define pb push_back
#define popb pop_back
#define fi first
#define sc second
#define endl '\n'
#define pll pair<ll,ll>
#define pld pair<ld,ld>
#define sz(a) (ll)(a.size())
#define all(a) a.begin(),a.end()
#define ceri(a,l,r) {cerr<<#a<<": ";for(ll i_ = l;i_<=r;i_++) cerr<<a[i_]<< " ";cerr<<endl;}
#define daj_mi_malo_vremena ios_base::sync_with_stdio(false);cerr.tie(0);cout.tie(0);cin.tie(0);

using namespace std;
using namespace __gnu_pbds;
/*
ll add(ll x,ll y){
    x+=y;
    if(x<0){
        x%=mod;
        x+=mod;
    }else{
        if(x>=mod) x%=mod;
    }
    return x;
}
ll mul(ll a,ll b){
	ll ans = (a*b)%mod;
	if(ans<0) ans+=mod;
	return ans;
}
*/
typedef tree<int,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
typedef tree<int,null_type,less_equal<ll>,rb_tree_tag,tree_order_statistics_node_update> ordered_multiset;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll rnd(ll l,ll r){
    return uniform_int_distribution<ll>(l,r)(rng);
}
#define maxn 200005
ll n;
vector<ll> g[maxn];
ll c[maxn];
ll dp[maxn][2];
void dfs(ll u,ll p){
    ll mx = 0;
    ll mx1 = 0;
    ll mx0 = 0;
    ll sum = 0;
    for(ll s : g[u]){
        if(s==p) continue;
        dfs(s,u);
        mx = max({mx,dp[s][0],dp[s][1]-1});
        mx1 = max(mx1,dp[s][1]);
        mx0 = max(mx0,dp[s][0]);
        sum+=dp[s][0];
    }
    dp[u][0] = max(sum-c[u],c[u]);
    if(c[u]&&mx!=0) dp[u][1] = mx + c[u];
    else dp[u][1] = mx1;
    //cerr<<"u: " <<u<< " "<< c[u]<< " "<<dp[u][0]<< " "<<dp[u][1]<<endl;
}
int main(){
	daj_mi_malo_vremena
    cin >> n;
    for(ll i = 1;i<=n-1;i++){
        ll x,y; cin >> x >> y;
        g[x].pb(y); g[y].pb(x);
    }
    ll sum = 0;
    {
        string s; cin >> s;
        for(ll i = 1;i<=n;i++) c[i] = s[i-1]-'0';
        for(ll i = 1;i<=n;i++) sum+=c[i];
    }
    if(sum==0){cout<<0<<endl; return 0;}
    dfs(1,1);
    //ceri(c,1,n);
    //for(ll i = 1;i<=n;i++) cerr<<dp[i][0]<< " ";
    //cerr<<endl;
    //for(ll i = 1;i<=n;i++) cerr<<dp[i][1]<< " ";
    //cerr<<endl;
    cout<<max({1LL,dp[1][0],dp[1][1]})<<endl;
	return 0;
}

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