Submission #97564

#	Time	Username	Problem	Language	Result	Execution time	Memory
97564		oolimry	Fireworks (APIO16_fireworks)	C++14	100 / 100	416 ms	68768 KiB

fireworks

#include <bits/stdc++.h>
using namespace std;
typedef pair<int, long long> ii;
vector<ii> adj[300005];
long long val[300005];
long long pw[300005];
priority_queue<long long> pq[300005];
void dfs(int u){
    if(adj[u].size() == 0){
        pq[u].push(pw[u]);
        pq[u].push(pw[u]);
        val[u] = 0;
        return;
    }
    long long highest = 0;
    for(long long i = 0;i < adj[u].size();i++){
        int v = adj[u][i].first;
        long long w = adj[u][i].second;
        dfs(v);
        if(pq[u].empty())
            highest += val[v];
        else if(pq[u].top() > pq[v].top())
            highest += val[v] + abs(pq[v].top() - pq[u].top());
        else
            highest += val[v] + (i) * abs(pq[v].top() - pq[u].top());
        if(pq[v].size() > pq[u].size()) swap(pq[v],pq[u]);
        while(!pq[v].empty()){
            pq[u].push(pq[v].top());
            pq[v].pop();
        }
    }
    long long flatr;
    ///flatening out the line
    for(long long i = 0;i < adj[u].size();i++){
        flatr = pq[u].top();
        pq[u].pop();
        highest -= (adj[u].size() - i-1) * abs(flatr - pq[u].top());
    }
    val[u] = highest;
    long long flatl = pq[u].top();
    pq[u].pop();
    pq[u].push(pw[u] + flatl);
    pq[u].push(pw[u] + flatr);
}
int main()
{
    //freopen("i.txt","r",stdin);
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n, m;
    cin >> n >> m;
    n += m;
    for(int i = 1;i < n;i++){
        long long a, b;
        cin >> a >> b;
        adj[a-1].push_back(ii(i,b));
        pw[i] = b;
    }
    pw[0] = 0;
    fill(val,val+n,0);
    dfs(0);
    cout << val[0];
    return 0;
}

Compilation message (stderr)

fireworks.cpp: In function 'void dfs(int)':
fireworks.cpp:16:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(long long i = 0;i < adj[u].size();i++){
                         ~~^~~~~~~~~~~~~~~
fireworks.cpp:18:19: warning: unused variable 'w' [-Wunused-variable]
         long long w = adj[u][i].second;
                   ^
fireworks.cpp:34:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(long long i = 0;i < adj[u].size();i++){
                         ~~^~~~~~~~~~~~~~~
fireworks.cpp:43:22: warning: 'flatr' may be used uninitialized in this function [-Wmaybe-uninitialized]
     pq[u].push(pw[u] + flatr);
                ~~~~~~^~~~~~~

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