Submission #3373771

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Source Code Expand

#include<bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)n;i++)
#define all(c) (c).begin(),(c).end()
#define pb push_back
#define dbg(...) do{cerr<<__LINE__<<": ";dbgprint(#__VA_ARGS__, __VA_ARGS__);}while(0);

using namespace std;

namespace std{template<class S,class T>struct hash<pair<S,T>>{size_t operator()(const pair<S,T>&p)const{return ((size_t)1e9+7)*hash<S>()(p.first)+hash<T>()(p.second);}};template<class T>struct hash<vector<T>>{size_t operator()(const vector<T> &v)const{size_t h=0;for(auto i : v)h=h*((size_t)1e9+7)+hash<T>()(i)+1;return h;}};}
template<class T>ostream& operator<<(ostream &os, const vector<T> &v){os<<"[ ";rep(i,v.size())os<<v[i]<<(i==v.size()-1?" ]":", ");return os;}template<class T>ostream& operator<<(ostream &os,const set<T> &v){os<<"{ "; for(const auto &i:v)os<<i<<", ";return os<<"}";}
template<class T,class U>ostream& operator<<(ostream &os,const map<T,U> &v){os<<"{";for(const auto &i:v)os<<" "<<i.first<<": "<<i.second<<",";return os<<"}";}template<class T,class U>ostream& operator<<(ostream &os,const pair<T,U> &p){return os<<"("<<p.first<<", "<<p.second<<")";}
void dbgprint(const string &fmt){cerr<<endl;}template<class H,class... T>void dbgprint(const string &fmt,const H &h,const T&... r){cerr<<fmt.substr(0,fmt.find(","))<<"= "<<h<<" ";dbgprint(fmt.substr(fmt.find(",")+1),r...);}
typedef long long ll;typedef vector<int> vi;typedef pair<int,int> pi;const int inf = (int)1e9;const double INF = 1e12, EPS = 1e-9;

void rec(int c, const vector<vi> &e, vi &v, vector<ll> &w){
	v[c] = 1;
	for(int i: e[c]){
		rec(i, e, v, w);
		v[c] += v[i];
		w[c] += w[i];
	}
}
int main(){
	cin.tie(0); cin.sync_with_stdio(0);
	int n, x, d; cin >> n >> x >> d;
	vector<vi> e(n);
	vi v(n), rem(n);
	vector<ll> w(n);
	rep(i, n){
		cin >> w[i];
		if(i){
			int p; cin >> p; p--;
			e[p].pb(i);
		}
	}
	rec(0, e, v, w);
	
	//dbg(v); dbg(w);
	
	const int N = 3000;
	vector<ll> dp(N, (ll)1e18);
	dp[0] = 0;
	rep(i, n) for(int j = N - 1; j >= 0; j--) if(dp[j] < 1e18){
		int cnt = i == 0 ? inf : d, use = min(cnt, 50);
		rem[i] = cnt - use;
		
		for(int k = 1; k <= use; k++){
			int nj = j + k * v[i];
			if(nj >= N || dp[j] + k * w[i] > x) break;
			dp[nj] = min(dp[nj], dp[j] + k * w[i]);
		}
	}
	
	vector<tuple<int, ll, int>> u;
	rep(i, n) u.emplace_back(v[i], w[i], rem[i]);
	
	sort(all(u), [](tuple<int, ll, int> a, tuple<int, ll, int> b)
			{ return get<1>(a) * get<0>(b) < get<1>(b) * get<0>(a); }
	);
	
	ll ans = 0;
	rep(i, N) if(dp[i] <= x){
		ll cnt = i;
		ll cost = dp[i];
		for(auto j : u) if(cost < x){
			ll k = min((ll)get<2>(j), (x - cost) / get<1>(j));
			cnt += k * get<0>(j);
			cost += k * get<1>(j);
		}
		ans = max(ans, cnt);
	}
	cout << ans << endl;
	
	return 0;
}

Submission Info

Judge Result