Submission #1002229

#	Time	Username	Problem	Language	Result	Execution time	Memory
1002229		vjudge1	Fireworks (APIO16_fireworks)	C++17	100 / 100	241 ms	76832 KiB

fireworks

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
 
const int  N = 4e5 + 30, MOD = 1e9 + 7;
int n,m;
vector<pair<int,int>> g[N];
multiset<ll> st[N];
ll h[N],l[N],r[N];
int mx[N];
void merge(int v,int to){
    if((int)st[v].size() < (int)st[to].size()){
        st[v].swap(st[to]);
        swap(mx[v],mx[to]);
        swap(l[v],l[to]);
        swap(r[v],r[to]);
    }
    mx[v]+=mx[to];
    for(ll j:st[to]){
        st[v].insert(j);
    }
    st[to].clear();
}
void dfs(int v,int W = 0){
    if(g[v].empty()){
        st[v].insert(W);
        st[v].insert(W);
        mx[v] = 1;
        h[v] = 0;
        l[v] = r[v] = W;
        return;
    }
    for(auto [to,w]:g[v]){
        dfs(to,w);
        merge(v,to);
    }
    assert(mx[v] == (int)g[v].size());
    while(mx[v] > 1){
        mx[v]--;
        st[v].erase(st[v].find(*st[v].rbegin()));
    }
    ll x = (*st[v].rbegin());
    st[v].erase(st[v].find(*st[v].rbegin()));
    ll y = (*st[v].rbegin());
    st[v].erase(st[v].find(*st[v].rbegin()));
    st[v].insert(x + W);
    st[v].insert(y + W);
    r[v] = (*st[v].rbegin());
    l[v] = (*(++(st[v].rbegin())));
}
ll E = 0;
void test(){
    cin >> n >> m;
    for(int i = 2;i <= n + m;i++){
        int a,b;
        cin >> a >> b;
        g[a].push_back({i,b});
        E += b;
    }
    dfs(1);
    st[1].erase(--st[1].end());
    ll H = 0;
    for(ll i:st[1]){
        E -= i;
    }
    cout << E << '\n';
}
signed main() {
    ios_base::sync_with_stdio(false);cin.tie(0);
    int t = 1;
    // cin >> t;
    while(t--){
        test();
    }
}

Compilation message (stderr)

fireworks.cpp: In function 'void test()':
fireworks.cpp:64:8: warning: unused variable 'H' [-Wunused-variable]
   64 |     ll H = 0;
      |        ^

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