Submission #633438

#	Time	Username	Problem	Language	Result	Execution time	Memory
633438		iomoon191	Power Plant (JOI20_power)	C++17	0 / 100	3 ms	6100 KiB

power

#include<bits/stdc++.h>
// #define int long long
#define all(a) (a).begin(), (a).end()
#define sz(a) (int)(a).size()
#define pb push_back
#define eb emplace_back
#define For(i,a,b) for(int i=(a); i<=(b); ++i)
#define roF(i,a,b) for(int i=(a); i>=(b); --i)
#define fi first
#define se second
#define mod 998244353
using namespace std;
// using namespace atcoder;
#ifdef DEBUG__
struct db_os{
    ostream& os;
    bool chk;
    template<class T> auto operator<<(T&& x){
        if(!chk) os << ", ";
        chk=0;
        os << x;
        return *this;
    }
};
template<class... T> void db_out(T&&... t){
    (db_os{cerr, 1} << ... << t);
}
#define dbg(...)                                       \
    do{                                                 \
        cerr << __LINE__ << ":" << #__VA_ARGS__ << "=";  \
        db_out(__VA_ARGS__);                              \
        cerr << "\n";                                      \
    }while(0);
#else
#define dbg(...)
#endif
typedef vector<int> vi;
typedef pair<int, int> pi;
typedef long long ll;
typedef long double ld;
const int N=250005;
const ll inf=0x3f3f3f3f;
mt19937 rng(random_device {}()); 
int rand(int a){
    return rng()%a;
}
int n, par[N], le[N], dp[N];
vi adj[N], vc;
char s[N];
void dfs(int u, int p=-1){
    vc.pb(u);
    for(auto &i: adj[u]){
        if(i == p) continue;
        par[i]=u;
        dfs(i, u);
    }
}
void rmain(){
    cin >> n;
    For(i,2,n){
        int u, v; cin >> u >> v;
        adj[u].pb(v);
        adj[v].pb(u);
    }
    //string s; cin >> s;
    int cnt=0;
    For(i,1,n){
        cin >> s[i];
        cnt+=(s[i] == 1);
        s[i]-='0';
    }
    int res=min(cnt, 2);
    dfs(1);
    reverse(all(vc));
    for(auto &v: vc){
        dp[v]=-s[v];
        for(auto &u: adj[v]){
            dp[v]+=(u != par[v] ? dp[u] : 0);
        }
        dp[v]=max(dp[v], (int)s[v]);
    }
    reverse(all(vc));
    for(auto &v: vc){
        int ne=-s[v];
        for(auto &i: adj[v]){
            ne+=(i == par[v] ? le[v] : dp[i]);
        }
        for(auto &i: adj[v]){
            if(i == par[v]) continue;
            le[i]=max((int)s[v], ne-dp[i]);
        }
    }
    For(i,1,n){
        int ne=-s[i];
        for(auto &j: adj[i]){
            ne+=(j == par[i] ? le[i] : dp[j]);
        }
        res=max(res, ne);
    }
    cout << res;
}

signed main(int argc, char *argv[]){
    iostream::sync_with_stdio(0);
    int T=1;
    while(T--) rmain();
    return 0;
}

• Subtask 1: 0 / 6
• Subtask 2: 0 / 41
• Subtask 3: 0 / 53