Submission #1121315

#	Time	Username	Problem	Language	Result	Execution time	Memory
1121315		yeediot	Fireworks (APIO16_fireworks)	C++17	100 / 100	129 ms	60652 KiB

fireworks

#pragma GCC optimize("O3")
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define sz(x) (int)(x.size())
const int mxn = 3e5 + 5;
inline char gc()
{
    const static int SZ = 1 << 16;
    static char buf[SZ], *p1, *p2;
    if (p1 == p2 && (p2 = buf + fread(p1 = buf, 1, SZ, stdin), p1 == p2))
        return -1;
    return *p1++;
}
inline void rd() {}
template <typename T, typename... U>
inline void rd(T &x, U &...y)
{
    x = 0;
    bool f = 0;
    char c = gc();
    while (isdigit(c))
        x = (x << 1) + (x << 3) + (c ^ 48), c = gc();
    f && (x = -x), rd(y...);
}
template <typename T>
inline void prt(T x)
{
    if (x > 9)
        prt(x / 10);
    putchar((x % 10) ^ 48);
}
vector<int>adj[mxn];
int n, m, l[mxn];
inline priority_queue<long long> dfs(int v, int pa){
    priority_queue<long long>pq;
    if(v > n){
        pq.push(l[v]), pq.push(l[v]);
        return pq;
    }
    for(auto u : adj[v]){
        if(u == pa) continue;
        auto pq2 = dfs(u, v);
        if(sz(pq) < sz(pq2)) swap(pq, pq2);
        while(sz(pq2)){
            pq.push(pq2.top());
            pq2.pop();
        }
    }
    for(int i = 1; i < sz(adj[v]); i++){
        pq.pop();
    }
    long long R = pq.top(); pq.pop();
    long long L = pq.top(); pq.pop();
    pq.push(l[v] + L), pq.push(l[v] + R);
    return pq;
}
inline void solve(){
    rd(n), rd(m);
    long long sum = 0, prev = 0;
    int slp = 1;
    for(int i = 2; i <= n + m; i++){
        int a;
        rd(a), rd(l[i]);
        sum += l[i];
        adj[a].pb(i);
    }
    auto pq = dfs(1, 1);
    pq.push(0);
    while(sz(pq)>1){
        long long cur = pq.top();
        pq.pop();
        slp--;
        sum += (cur - pq.top()) * slp;
    }
    prt(sum);
}
signed main(){
    solve();
}

Compilation message (stderr)

fireworks.cpp: In function 'void solve()':
fireworks.cpp:60:24: warning: unused variable 'prev' [-Wunused-variable]
   60 |     long long sum = 0, prev = 0;
      |                        ^~~~

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