This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
#define int long long 
vector<int> adj[300005];
int a[300005];
deque<int> v[300005];
int mn[300005], sm[300005];
void dfs(int x) {
	v[x].push_back(a[x]);
	sm[x] = a[x];
	mn[x] = min(a[x], 0LL);
	vector<pair<int, int>> vec;
	for(int i : adj[x]) {
		dfs(i);
		vec.push_back({-mn[i],i});
	}
	sort(vec.begin(), vec.end());
	for(auto [m, idx] : vec) {
		m = -m;
		if(v[x].size() < v[idx].size()) {
			swap(v[x], v[idx]);
			while(v[idx].size()) {
				v[x].push_front(v[idx].back());
				v[idx].pop_back();
			}
		} else {
			while(v[idx].size()) {
				v[x].push_back(v[idx].front());
				v[idx].pop_front();
			}
		}
		mn[x] = min(mn[x], sm[x]+m);
		sm[x] += sm[idx];
	}
	if(sm[x] <= 0) {
		v[x].clear();
		sm[x] = mn[x] = 0;
	}
}
int32_t main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	int n, s, x, ans = 0, cur = 0;
	cin >> n >> s;
	a[0] = s;
	for(int i = 1; i <= n; i++) {
		cin >> a[i] >> x;
		adj[x].push_back(i);
	}
	dfs(0);
	for(int i : v[0]) {
		cur += i;
		if(cur < 0) break;
		ans = max(ans, cur);
	}
	cout << ans-s;
}
Compilation message (stderr)
Main.cpp: In function 'void dfs(long long int)':
Main.cpp:21:11: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   21 |  for(auto [m, idx] : vec) {
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