Submission #401034

#	Time	Username	Problem	Language	Result	Execution time	Memory
401034		Falcon	Power Plant (JOI20_power)	C++17	100 / 100	197 ms	29604 KiB

power

#pragma GCC optimize("O2")

#include <bits/stdc++.h>

#ifdef DEBUG
#include "debug.hpp"
#endif

using namespace std;

#define all(c)              (c).begin(), (c).end()
#define rall(c)             (c).rbegin(), (c).rend()
#define traverse(c, it)     for(auto it = (c).begin(); it != (c).end(); ++it)
#define rep(i, N)           for(int i = 0; i < (N); ++i)
#define rrep(i, N)          for(int i = (N) - 1; i >= 0; --i)
#define rep1(i, N)          for(int i = 1; i <= (N); ++i)
#define rep2(i, s, e)       for(int i = (s); i <= (e); ++i)
#define rep3(i, s, e, d)    for(int i = (s); (d) >= 0 ? i <= (e) : i >= (e); i += (d))

#ifdef DEBUG
#define debug(x...)         { \
                            ++dbg::depth; \
                            string dbg_vals = dbg::to_string(x); \
                            --dbg::depth; \
                            dbg::fprint(__func__, __LINE__, #x, dbg_vals); \
                            }

#define light_debug(x)      { \
                            dbg::light = true; \
                            dbg::dout << __func__ << ":" << __LINE__; \
                            dbg::dout << "  " << #x << " = " << x << endl; \
                            dbg::light = false; \
                            }
#else
#define debug(x...)         42
#define light_debug(x)      42
#endif


using ll = long long;

template<typename T>
inline T& ckmin(T& a, T b) { return a = a > b ? b : a; }

template<typename T>
inline T& ckmax(T& a, T b) { return a = a < b ? b : a; }

template<class Fun>
class y_combinator_result {
    Fun fun_;
public:
    template<class T>
    explicit y_combinator_result(T &&fun): fun_(std::forward<T>(fun)) {}

    template<class ...Args>
    decltype(auto) operator()(Args &&...args) {
        return fun_(std::ref(*this), std::forward<Args>(args)...);
    }
};

template<class Fun>
decltype(auto) y_combinator(Fun &&fun) {
    return y_combinator_result<std::decay_t<Fun>>(std::forward<Fun>(fun));
}


int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    
    #ifdef DEBUG
    freopen("debug", "w", stderr);
    #endif

    int n; cin >> n;
    vector<vector<int>> adj(n);
    vector<int> dp_0(n), dp_1(n);

    rep(_, n - 1) {
        int a, b; cin >> a >> b; --a, --b;
        adj[a].push_back(b), adj[b].push_back(a);
    }

    string s; cin >> s;

    y_combinator([&](auto dfs, int v, int p) -> void {
            for(int u : adj[v]) if(u != p) dfs(u, v);            

            int t{}, g{s[v] == '1'};
            dp_1[v] = g;
            for(int u : adj[v]) if(u != p)
                t += dp_1[u];
            ckmax(dp_1[v], t - g);

            dp_0[v] = dp_1[v];
            for(int u : adj[v]) if(u != p)
                ckmax(dp_0[v], max(dp_0[u], g + dp_1[u]));

            })(0, -1);

    cout << dp_0[0] << '\n';
    

    #ifdef DEBUG
    dbg::dout << "\nExecution time: " << clock() * 1000 / CLOCKS_PER_SEC  << "ms" << endl;
    #endif

    return 0;
}

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