Submission #1166801

#	Time	Username	Problem	Language	Result	Execution time	Memory
1166801		SmuggingSpun	Fireworks (APIO16_fireworks)	C++20	7 / 100	0 ms	332 KiB

fireworks

#include<bits/stdc++.h>
#define taskname "B"
using namespace std;
typedef long long ll;
template<class T>bool minimize(T& a, T b){
    if(a > b){
        a = b;
        return true;
    }
    return false;
}
int n, m;
namespace sub1{
    void solve(){
        vector<int>a(m);
        for(int& x : a){
            cin >> x >> x;
        }
        sort(a.begin(), a.end());
        int median = a[m >> 1];
        ll ans = 0;
        for(int& x : a){
            ans += abs(x - median);
        }
        cout << ans;
    }
}
namespace sub23{
    const int lim = 5e3 + 5;
    const ll INF = 1e18;
    vector<pair<int, int>>g[lim];
    ll ans = 0;
    pair<ll, ll>dfs(int s){
        if(s > n){
            return make_pair(0, 0);
        }
        vector<pair<ll, ll>>a;
        for(auto& [d, w] : g[s]){
            auto [l, r] = dfs(d);
            a.emplace_back(l + w, r + w);
        }
        vector<ll>candidate;
        for(auto& [l, r] : a){
            candidate.emplace_back(l);
            candidate.emplace_back(r);
        }
        sort(candidate.begin(), candidate.end());
        candidate.resize(unique(candidate.begin(), candidate.end()) - candidate.begin());
        vector<ll>ret;
        ll opt = INF;
        for(ll& value : candidate){
            ll cur = 0;
            for(auto& [l, r] : a){
                if(l > value || r < value){
                    cur += min(abs(l - value), abs(r - value));
                }
            }
            if(minimize(opt, cur)){
                ret.clear();
            }
            if(opt == cur){
                ret.emplace_back(value);
            }
        }
        ans += opt;
        return make_pair(ret[0], ret.back());
    }
    void solve(){
        for(int i = 2; i <= n + m; i++){
            int p, c;
            cin >> p >> c;
            g[p].emplace_back(i, c);
        }
        dfs(1);
        cout << ans;
    }
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
    cin >> n >> m;
    if(n == 1){
        sub23::solve();
    }
    else if(n + m <= 5000){
        sub23::solve();
    }
}

Compilation message (stderr)

fireworks.cpp: In function 'int main()':
fireworks.cpp:81:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   81 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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