Submission #625392

#	Time	Username	Problem	Language	Result	Execution time	Memory
625392		socpite	Fireworks (APIO16_fireworks)	C++14	7 / 100	5 ms	7356 KiB

fireworks

#include<bits/stdc++.h>
using namespace std;

#define f first
#define s second

typedef long long ll;

const int maxn = 3e5+5;
const ll inf = 1e18;

ll ans = 0;

int n, m;
int w[maxn];
vector<int> tree[maxn];

pair<ll, int> dfs(int x){
    if(x > n)return {w[x], w[x]};
    vector<pair<ll, int>> op;
    for(auto v: tree[x]){
        auto tmp = dfs(v);
        op.push_back({tmp.f, 0});
        op.push_back({tmp.s, 1});
    }
    sort(op.begin(), op.end());
    ll mid = op[op.size()/2].f;
    for(auto v: op){
        if(v.s)ans += max(0LL, mid - v.f);
        else ans += max(0LL, v.f-mid);
    }
    return {op[op.size()/2-1].f+w[x], op[op.size()/2].f+w[x]};
}

int main(){
    cin >> n >> m;
    for(int i = 2; i <= n+m; i++){
        int x;
        cin >> x >> w[i];
        tree[x].push_back(i);
    }
    dfs(1);
    cout << ans;
}

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