Submission #707677

#	Time	Username	Problem	Language	Result	Execution time	Memory
707677		_martynas	Fireworks (APIO16_fireworks)	C++11	7 / 100	10 ms	14424 KiB

fireworks

#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using pii = pair<int, int>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<ll>;

#define F first
#define S second
#define PB push_back
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()

void FASTIO() {ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); }

const int MXN = 6e5+5;

int n, m;
vi adj[MXN];
ll C[MXN];
pll interval[MXN];
ll ans;

void dfs(int u) {
    if(adj[u].empty()) {
        interval[u] = {0, 0};
        return;
    }
    vl X;
    for(int v : adj[u]) {
        dfs(v);
        X.PB(interval[v].F+C[v]);
        X.PB(interval[v].S+C[v]);
    }
    sort(all(X));
    int k = X.size();
    for(int v : adj[u]) {
        if(interval[v].F+C[v] <= X[k/2-1] && X[k/2-1] <= interval[v].S+C[v]) continue;
        ans += min(labs(X[k/2-1]-(interval[v].F+C[v])), labs(X[k/2-1]-(interval[v].S+C[v])));
    }
    interval[u] = {X[k/2-1], X[k/2]};
}

int main() {
    FASTIO();
    cin >> n >> m;
    for(int i = 2; i <= n+m; i++) {
        int p; cin >> p >> C[i];
        adj[p].PB(i);
    }
    dfs(1);
    cout << ans << "\n";
    return 0;
}

/*



*/

• Subtask 1: 7 / 7
• Subtask 2: 0 / 19
• Subtask 3: 0 / 29
• Subtask 4: 0 / 45