Submission #1059946

#	Time	Username	Problem	Language	Result	Execution time	Memory
1059946		steveonalex	Power Plant (JOI20_power)	C++17	100 / 100	70 ms	30596 KiB

power

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
#define block_of_code if(true)
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(a, b);}
ll lcm(ll a, ll b){return a / gcd(a, b) * b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }



const int N = 2e5 + 69;
const int INF = 1e9 + 69;

int n;
vector<int> graph[N];
int e[N];
int dp[N][2];
int ans = 0;

void dfs(int u, int p){
    dp[u][0] = 0;
    dp[u][1] = e[u];
    int sum = -e[u];
    for(int v: graph[u]) if (v != p){
        dfs(v, u);
        maximize(ans, max(dp[v][0], dp[v][1]) + e[u]);
        sum += max(dp[v][0], dp[v][1]);
    }
    maximize(dp[u][1], sum);
    maximize(ans, dp[u][1]);

    // cout << u << " " << dp[u][0] << " " << dp[u][1] << "\n";
}

int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);


    clock_t start = clock();

    cin >> n;
    for(int i = 1; i<n; ++i){
        int u, v; cin >> u >> v;
        graph[u].push_back(v);
        graph[v].push_back(u);
    }

    string s; cin >> s;
    for(int i = 0; i<n; ++i) e[i+1] = s[i] == '1';

    dfs(1, 0);

    cout << ans << "\n";

    cerr << "Time elapsed: " << clock() - start << " ms\n";


    return 0;
}

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