Submission #1279496

#	Time	Username	Problem	Language	Result	Execution time	Memory
1279496		InvMOD	Power Plant (JOI20_power)	C++17	100 / 100	99 ms	31336 KiB

power

#include<bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define pb push_back
#define eb emplace_back

#define vi vector<int>
#define pi pair<int,int>
#define sz(v) (int)(v).size()
#define all(v) (v).begin(), (v).end()
#define compact(v) (v).erase(unique(all(v)), (v).end())

template<class T> using upq = priority_queue<T, vector<T>, greater<T>>;
template<class T> int lwrbound(const vector<T>& a, const T& b, const int s = 0){return int(lower_bound(s + all(a), b) - a.begin());}
template<class T> int uprbound(const vector<T>& a, const T& b, const int s = 0){return int(upper_bound(s + all(a), b) - a.begin());}

#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 sumof(x) accumulate(all(x), 0ll)
#define dbg(x) "[" << #x " = " << (x) << "]"
#define el "\n"

using ll = long long;
using ld = long double;

template<class T> bool ckmx(T& a, const T b){return (a < b ? a = b, true : false);}
template<class T> bool ckmn(T& a, const T b){return (a > b ? a = b, true : false);}

const int N = 2e5 + 5;
const int MOD = 1e9 + 7;
const ll INF = numeric_limits<ll>::max() / 8;



void Main()
{
    int n; cin >> n;

    vector<vi> adj(n + 1);
    FOR(i, 2, n){
        int u,v; cin >> u >> v;
        adj[u].eb(v), adj[v].eb(u);
    }

    vector<bool> gen(n + 1);
    FOR(i, 1, n){
        char c; cin >> c;
        gen[i] = (c - '0');
    }

    vi dp(n + 1); int ans = 0;
    function<void(int,int)> dfs = [&](int x, int p) -> void{
        for(int v : adj[x])if(v != p){
            dfs(v, x);
            dp[x] += dp[v];
            ckmx(ans, dp[v] + gen[x]);
        }

        if(gen[x]){
            --dp[x];
            ckmx(dp[x], 1);
            ckmx(ans, dp[x]);
        }
        else{
            ckmx(dp[x], 0);
            ckmx(ans, dp[x]);
        }
    };
    dfs(1, -1);

    cout << ans << el;
}

int32_t main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    #define name "InvMOD"
    if(fopen(name".INP", "r")){
        freopen(name".INP", "r", stdin);
        freopen(name".OUT", "w", stdout);
    }

    int t = 1; while(t--) Main();
    return 0;
}

Compilation message (stderr)

power.cpp: In function 'int32_t main()':
power.cpp:84:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   84 |         freopen(name".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
power.cpp:85:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   85 |         freopen(name".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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