Submission #1110532

#	Time	Username	Problem	Language	Result	Execution time	Memory
1110532		vladilius	Election Campaign (JOI15_election_campaign)	C++17	100 / 100	143 ms	36504 KiB

election_campaign

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define pb push_back
#define ff first
#define ss second
#define arr3 array<int, 3>

struct FT{
    vector<ll> bit;
    int n;
    FT(int ns){
        n = ns;
        bit.resize(n + 1);
    }
    void add(int v, ll x){
        while (v <= n){
            bit[v] += x;
            v |= (v + 1);
        }
    }
    void add(int l, int r, ll x){
        add(l, x);
        add(r + 1, -x);
    }
    ll get(int v){
        ll out = 0;
        while (v > 0){
            out += bit[v];
            v = (v & (v + 1)) - 1;
        }
        return out;
    }
};

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    
    int n; cin>>n;
    vector<int> g[n + 1];
    for (int i = 1; i < n; i++){
        int x, y; cin>>x>>y;
        g[x].pb(y);
        g[y].pb(x);
    }

    const int lg = log2(n);
    vector<vector<int>> pw(n + 1, vector<int>(lg + 1));
    vector<int> tin(n + 1), tout(n + 1);
    int timer = 0;
    function<void(int, int)> fill = [&](int v, int pr){
        pw[v][0] = pr;
        for (int i = 1; i <= lg; i++){
            pw[v][i] = pw[pw[v][i - 1]][i - 1];
        }
        tin[v] = ++timer;
        for (int i: g[v]){
            if (i == pr) continue;
            fill(i, v);
        }
        tout[v] = timer;
    };
    fill(1, 1);
    
    auto check = [&](int x, int y){
        return (tin[x] <= tin[y] && tout[x] >= tout[y]);
    };
    auto lca = [&](int x, int y){
        if (check(x, y)) return x;
        if (check(y, x)) return y;
        for (int i = lg; i >= 0; i--){
            if (!check(pw[x][i], y)){
                x = pw[x][i];
            }
        }
        return pw[x][0];
    };
    
    vector<arr3> t[n + 1];
    int m; cin>>m;
    while (m--){
        int x, y, c; cin>>x>>y>>c;
        t[lca(x, y)].pb({x, y, c});
    }
    
    FT T(n);
    vector<ll> dp(n + 1);
    function<void(int, int)> dfs = [&](int v, int pr){
        ll S = 0;
        for (int i: g[v]){
            if (i == pr) continue;
            dfs(i, v);
            S += dp[i];
        }
        
        dp[v] = S;
        for (auto [x, y, c]: t[v]){
            dp[v] = max(dp[v], c + S + T.get(tin[x]) + T.get(tin[y]));
        }
        T.add(tin[v], tout[v], S - dp[v]);
    };
    dfs(1, 0);
    
    cout<<dp[1]<<"\n";
}

• Subtask 1: 10 / 10
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 30 / 30
• Subtask 5: 10 / 10
• Subtask 6: 40 / 40