Submission #1250782

#	Time	Username	Problem	Language	Result	Execution time	Memory
1250782		mingga	Jobs (BOI24_jobs)	C++20	0 / 100	79 ms	22592 KiB

Main

// Author: caption_mingle
#include "bits/stdc++.h"

using namespace std;

#define ln "\n"
#define pb push_back
#define fi first
#define se second
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
#define int long long
const int mod = 1e9 + 7;
const int inf = 2e18;
const int N = 3e5 + 7;
int n, s, a[N], p[N];

struct SEGTREE {
	int n;
	vector<pair<int, int>> st;
	vector<int> lazy;
	SEGTREE() {}
	SEGTREE(int n) {
		st.resize(n * 4 + 4, {0, 0});
		lazy.resize(n * 4 + 4, 0);
	}
	void build(int i, int l, int r) {
		if(l == r) {
			st[i] = {-inf, l};
			return;
		}
		int m = (l + r) >> 1;
		build(i * 2, l, m);
		build(i * 2 + 1, m + 1, r);
		st[i] = max(st[i * 2], st[i * 2 + 1]);
	}
	void down(int i) {
		if(lazy[i]) {
			int x = lazy[i];
			lazy[i] = 0;
			lazy[i * 2] += x;
			lazy[i * 2 + 1] += x;
			st[i * 2].fi += x;
			st[i * 2 + 1].fi += x;
		}
	}
	void update(int i, int l, int r, int u, int v, int x) {
		if(l > v or r < u) return;
		if(u <= l and r <= v) {
			st[i].fi += x;
			lazy[i] += x;
			return;
		}
		int m = (l + r) >> 1;
		update(i * 2, l, m, u, v, x);
		update(i * 2 + 1, m + 1, r, u, v, x);
		st[i] = max(st[i * 2], st[i * 2 + 1]);
	}

	pair<int, int> get(int i, int l, int r, int u, int v) {
		if(l > v or r < u) return {-inf, 0};
		if(u <= l and r <= v) return st[i];
		int m = (l + r) >> 1;
		return max(get(i * 2, l, m, u, v), get(i * 2 + 1, m + 1, r, u, v));
	}
};

namespace sub1 {
	bool check() {
		return s == 1e18;
	}
	int id[N], root[N], f[N];
	int cur = 0;
	vector<int> g[N];
	void dfs(int u) {
		id[u] = cur;
		for(int v : g[u]) {
			dfs(v);
		}
	}
	void dfs2(int u, int id, int cur) {
		f[id] = max(f[id], cur);
		for(int v : g[u]) {
			dfs2(v, id, cur + a[v]);
		} 
	}
	void solve() {
		for(int i = 1; i <= n; i++) {
			if(p[i] != 0) {
				g[p[i]].pb(i);
			} 
		}
		for(int i = 1; i <= n; i++) {
			if(p[i] == 0) {
				cur++;
				root[cur] = i;
				dfs(i);
			}
		}
		int ans = 0;
		for(int i = 1; i <= cur; i++) {
			dfs2(root[i], i, a[root[i]]);
			ans += f[i];
		}
		cout << ans << ln;
	}
}

namespace sub2 {
	bool check() {
		for(int i = 1; i <= n; i++) {
			if(p[i] == 0 or p[i] == i - 1) continue;
			return 0;
		}
		return 1;
	}
	int mn[N], val[N], lst[N], fir[N], grp[N];
	int gp = 0;
	void solve() {
		mn[0] = inf;
		for(int i = 1; i <= n; i++) {
			val[i] = val[p[i]] + a[i];
			mn[i] = min(val[i], mn[p[i]]);
			if(p[i] == 0) {
				grp[i] = ++gp;
				fir[gp] = i;
			} else grp[i] = grp[i - 1];
		}
		SEGTREE st = SEGTREE(n);
		st.build(1, 1, n);
		int ans = 0;
		for(int i = n; i > 0; i--) {
			if(p[i + 1] == 0) {
				lst[grp[i]] = i;
			}
		}
		vector<pair<int, int>> vec;
		for(int i = 1; i <= n; i++) {
			vec.pb({mn[i], i});
		}
		sort(all(vec), greater<pair<int, int>>());
		int i = 0;
		while(i < sz(vec)) {
			auto [min_val, u] = vec[i]; 
			if(min_val + s >= 0) {
				cerr << "UPDATE " << u << ' ' << min_val << ' ' << val[u] << ln;
				st.update(1, 1, n, u, u, val[u] + inf);
				i++;
			} else {
				auto [x, id] = st.st[1];
				cerr << "GET " << x << ' ' << id << ln;
				if(x <= 0) break;
				ans += x;
				s += x;
				int cur_grp = grp[id];
				int old_fir = fir[cur_grp];
				for(int j = old_fir; j <= id; j++) {
					st.update(1, 1, n, j, j, -1e15);
				}
				fir[cur_grp] = id + 1;
				if(fir[cur_grp] <= lst[cur_grp]) {
					st.update(1, 1, n, id + 1, lst[cur_grp], -val[id]);
				}
			}
		}
		auto [x, id] = st.st[1];
		// cerr << "GET " << x << ' ' << id << ln;
		if(x > 0) {
			ans += x;
			s += x;
		}
		cout << ans << ln;
	}
}

signed main() {
	cin.tie(0) -> sync_with_stdio(0);
	#define task ""
	if(fopen(task ".INP", "r")) {
		freopen(task ".INP", "r", stdin);
		freopen(task ".OUT", "w", stdout);
	}
	cin >> n >> s;
	for(int i = 1; i <= n; i++) {
		cin >> a[i] >> p[i];
	}
	if(sub1::check()) sub1::solve();
	else if(sub2::check()) sub2::solve();
    cerr << "\nTime: " << clock() * 1000 / CLOCKS_PER_SEC;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:180:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  180 |                 freopen(task ".INP", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:181:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  181 |                 freopen(task ".OUT", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 11
• Subtask 2: 0 / 14
• Subtask 3: 0 / 15
• Subtask 4: 0 / 29
• Subtask 5: 0 / 31