Submission #1098202

#	Time	Username	Problem	Language	Result	Execution time	Memory
1098202		LilPluton	Power Plant (JOI20_power)	C++14	100 / 100	184 ms	54812 KiB

power

#include <bits/stdc++.h>
using namespace std;
const int sz = 1e6 + 5;
#define int long long
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};

struct DSU{

    vector<int>e;
    DSU(int n){
        e.assign(n + 1, -1);
    }
    int _find(int v){
        if(e[v] < 0){
            return v;
        }
        return e[v] = _find(e[v]);
    }
    int _union(int u,int v){
        u = _find(u);
        v = _find(v);
        if(u != v){
            if(e[u] > e[v]){
                swap(u, v);
            }
            e[u] += e[v];
            e[v] = u;
            return 1;
        }
        return 0;
    }

};
string s;
int n, res;
vector<vector<int>>v(sz);
vector<int>dp(sz);
void dfs(int u,int p){
    int sum = 0;
    int mx = 0;
    for(auto i : v[u]){
        if(i == p){
            continue;
        }
        dfs(i, u);
        sum += dp[i];
        mx = max(mx, dp[i]);
    }
    dp[u] = max((int)(s[u] == '1'), sum - (s[u] == '1'));
    res = max(res, sum - (int)(s[u] == '1'));
    res = max(res, mx + (int)(s[u] == '1'));   
}

void test_case(int testcase){
    cin >> n;
    for(int i = 0; i < n - 1; ++i){
        int a, b;
        cin >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    cin >> s;
    s = '#' + s;
    dfs(1, -1);
    cout << res << endl;

}

signed main(){
    int T = 1;
    for(int test = 1; test <= T; ++test){
        test_case(test);
    } 
}

/*
    
*/

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