oj.uz

Submission #756032

# Submission time Handle Problem Language Result Execution time Memory
756032 2023-06-10T23:38:58 Z badont Cat in a tree (BOI17_catinatree) C++17
51 / 100
 1000 ms 45056 KB 
#include <iostream>
#include <algorithm>
#include <vector>
#include <cmath>
#include <cassert>
#include <array>
#include <numeric>
#include <set>
#include <queue>
using namespace std;
#define pb push_back
template<typename T, typename = void> struct is_iterable : false_type {};
template<typename T> struct is_iterable<T, void_t<decltype(begin(declval<T>())),decltype(end(declval<T>()))>> : true_type {};
template<typename T> typename enable_if<is_iterable<T>::value&&!is_same<T, string>::value,ostream&>::type operator<<(ostream &cout, T const &v);
template<typename A, typename B> ostream& operator<<(ostream &cout, pair<A, B> const &p) { return cout << "(" << p.f << ", " << p.s << ")"; }
template<typename T> typename enable_if<is_iterable<T>::value&&!is_same<T, string>::value,ostream&>::type operator<<(ostream &cout, T const &v) {
	cout << "["; 
	for (auto it = v.begin(); it != v.end();) {
		cout << *it;
		if (++it != v.end()) cout << ", ";
	}
	return cout << "]";
}
 
void dbg_out() { cout << endl; }
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T) { cout << ' ' << H; dbg_out(T...); }
 
#ifdef LOCAL
#define debug(...) cout << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define debug(...) "zzz"
#endif
 
#define all(x) x.begin(),x.end()
#define F0R(i,n) for (int i = 0; i < n; i++)
using ll = int;
 
//benq
constexpr ll INF = 1e7;
struct Lazy {
    ll app, x;
    Lazy(ll a, ll b) : app(a), x(b) {}
    Lazy() : app(INF), x(-INF) {}
    Lazy& operator+=(const Lazy& o) {
        this->app = min(this->app, o.app);
        this->x = max(this->x, o.x);
        return *this;
    }
};
struct Info {
    ll min_active, max_depth, best_min, best_max;
    Info() : min_active(INF), max_depth(-INF), best_min(INF), best_max(-INF) {}
    friend Info operator+(const Info& a, const Info& b) {
        Info ret;
        ll val_1 = a.best_min - 2 * a.best_max;
        ll val_2 = b.best_min - 2 * b.best_max;
        ret.min_active = min(a.min_active, b.min_active);
        ret.max_depth = max(a.max_depth, b.max_depth);

        if (val_1 < val_2)
            ret.best_min = a.best_min, ret.best_max = a.best_max;
        else 
            ret.best_min = b.best_min, ret.best_max = b.best_max;

        return ret;
    }
    Info& operator+=(const Lazy& o) {
        ll c_val = this->best_min - 2 * this->best_max;
        if (o.app - 2 * o.x < c_val) {
            c_val = o.app - 2 * o.x;
            this->best_min = o.app, this->best_max = o.x;
        }
        if (o.app - 2 * this->max_depth < c_val) {
            c_val = o.app - 2 * this->max_depth;
            this->best_min = o.app;
            this->best_max = this->max_depth;
        }

        if (this->min_active - 2 * o.x < c_val) {
            c_val = this->min_active - 2 * o.x;
            this->best_max = o.x;
            this->best_min = min_active; 
        }

        this->max_depth = max(this->max_depth, o.x);
        this->min_active = min(this->min_active, o.app);

        return *this;
    }
};
 
 
template<class T, int SZ, class Lazy> struct LazySeg { 
	//zero indexed
	static_assert(__builtin_popcount(SZ) == 1); // SZ must be power of 2
	const T ID{}; T cmb(const T& a, const T& b) { return a+b; }
	T seg[2*SZ];
    Lazy lazy[2*SZ]; 
	LazySeg() { F0R(i,2*SZ) seg[i] = {}, lazy[i] = {}; }
	void push(int ind, int L, int R) { /// modify values for current node
		seg[ind] += lazy[ind]; // dependent on operation
		if (L != R) F0R(i,2) lazy[2*ind+i] += lazy[ind]; /// prop to children
		lazy[ind] = {}; 
	} // recalc values for current node
	void pull(int ind){seg[ind]=cmb(seg[2*ind],seg[2*ind+1]);}
	void build() { for (int i = SZ - 1; i >= 1; --i) pull(i); }
	void upd(int lo,int hi,const Lazy& inc,int ind=1,int L=0, int R=SZ-1) {
		push(ind,L,R); if (hi < L || R < lo) return;
		if (lo <= L && R <= hi) { 
			lazy[ind] += inc; push(ind,L,R); return; }
		int M = (L+R)/2; upd(lo,hi,inc,2*ind,L,M); 
		upd(lo,hi,inc,2*ind+1,M+1,R); pull(ind);
	}
	T query(int lo, int hi, int ind=1, int L=0, int R=SZ-1) {
		push(ind,L,R); if (lo > R || L > hi) return ID;
		if (lo <= L && R <= hi) return seg[ind];
		int M = (L+R)/2; return cmb(query(lo,hi,2*ind,L,M),
			query(lo,hi,2*ind+1,M+1,R));
	}
};
 
template<int SZ, bool VALS_IN_EDGES> struct HLD { 
	int N; vector<int> adj[SZ];
	int par[SZ], root[SZ], depth[SZ], sz[SZ], ti;
	int pos[SZ]; vector<int> rpos; // rpos not used but could be useful
	void ae(int x, int y) { adj[x].pb(y), adj[y].pb(x); }
	void dfsSz(int x) { 
		sz[x] = 1; 
		for (auto& y : adj[x]) {
			par[y] = x; depth[y] = depth[x]+1;
			adj[y].erase(find(all(adj[y]),x)); /// remove parent from adj list
			dfsSz(y); sz[x] += sz[y];
			if (sz[y] > sz[adj[x][0]]) swap(y,adj[x][0]);
		}
	}
	void dfsHld(int x) {
		pos[x] = ti++; rpos.pb(x);
		for (auto& y : adj[x]) {
			root[y] = (y == adj[x][0] ? root[x] : y);
			dfsHld(y); }
	}
	void init(int _N, int R = 0) { N = _N; 
		par[R] = depth[R] = ti = 0; dfsSz(R); 
		root[R] = R; dfsHld(R); 
	}
	int lca(int x, int y) {
		for (; root[x] != root[y]; y = par[root[y]])
			if (depth[root[x]] > depth[root[y]]) swap(x,y);
		return depth[x] < depth[y] ? x : y;
	}
	/// int dist(int x, int y) { // # edges on path
	/// 	return depth[x]+depth[y]-2*depth[lca(x,y)]; }
	LazySeg<Info,SZ,Lazy> tree; // segtree for sum
	template <class BinaryOp>
	void processPath(int x, int y, BinaryOp op) {
		for (; root[x] != root[y]; y = par[root[y]]) {
			if (depth[root[x]] > depth[root[y]]) swap(x,y);
			op(pos[root[y]],pos[y]); }
		if (depth[x] > depth[y]) swap(x,y);
		op(pos[x]+VALS_IN_EDGES,pos[y]); 
	}
	void modifyPath(int x, int y, const Lazy& v) { 
		processPath(x,y,[this,&v](int l, int r) { 
			tree.upd(l,r,v); }); }
	Info queryPath(int x, int y) { 
		Info res = {}; processPath(x,y,[this,&res](int l, int r) { 
			res = res + tree.query(l,r); });
		return res; }
};
 
HLD<1<<18, false> hld;
 
void solve() {
    ll n, d;
    cin >> n >> d;
 
    vector e(n, vector<ll>());
    for (int i = 0; i < n - 1; i++) {
        ll x; cin >> x;
        e[i + 1].pb(x);
        e[x].pb(i + 1);
        hld.ae(x, i + 1);
    }
    hld.init(n, 0);
    vector<ll> depth(n);
    auto dfs = [&](auto& dfs, ll g, ll p, ll d) -> void {
        depth[g] = d;
        hld.modifyPath(g, g, Lazy(INF, depth[g]));
        for (auto u : e[g]) if (u != p) {
            dfs(dfs, u, g, d + 1);
        }
    };
    dfs(dfs, 0, -1, 0);
    vector<ll> p(n);
    iota(all(p), 0);
    sort(all(p), [&](ll x, ll y) {
        if (depth[x] == depth[y])
            return x > y;
        return depth[x] > depth[y];
    });
 
    vector<ll> ans;
    for (auto u : p) {
        Info to_root = hld.queryPath(0, u);
        ll root_val = to_root.best_min - 2LL * to_root.best_max;
        if (root_val + depth[u] >= d) {
            ans.pb(u);
            // activate u
            hld.modifyPath(0, u, Lazy(depth[u], -INF));
        }
    }
 
    sort(all(ans));
    cout << ans.size() << '\n';
    /*
    for (const auto& u : ans)
        cout << u + 1 << ' ';
    cout << '\n';
    */
}
 
int main() {
    cin.tie(0)->sync_with_stdio(false);
    solve();
    return 0;
}

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 18772 KB Output is correct
2 Correct 13 ms 18772 KB Output is correct
3 Correct 10 ms 18792 KB Output is correct
4 Correct 10 ms 18816 KB Output is correct
5 Correct 10 ms 18772 KB Output is correct
6 Correct 11 ms 18772 KB Output is correct
7 Correct 11 ms 18816 KB Output is correct
8 Correct 11 ms 18736 KB Output is correct
9 Correct 11 ms 18772 KB Output is correct
10 Correct 11 ms 18764 KB Output is correct
11 Correct 12 ms 18800 KB Output is correct
12 Correct 13 ms 18772 KB Output is correct
13 Correct 11 ms 18760 KB Output is correct
14 Correct 12 ms 18772 KB Output is correct
15 Correct 11 ms 18788 KB Output is correct
16 Correct 11 ms 18772 KB Output is correct
17 Correct 12 ms 18772 KB Output is correct
18 Correct 11 ms 18772 KB Output is correct
19 Correct 11 ms 18772 KB Output is correct
20 Correct 11 ms 18724 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 18772 KB Output is correct
2 Correct 13 ms 18772 KB Output is correct
3 Correct 10 ms 18792 KB Output is correct
4 Correct 10 ms 18816 KB Output is correct
5 Correct 10 ms 18772 KB Output is correct
6 Correct 11 ms 18772 KB Output is correct
7 Correct 11 ms 18816 KB Output is correct
8 Correct 11 ms 18736 KB Output is correct
9 Correct 11 ms 18772 KB Output is correct
10 Correct 11 ms 18764 KB Output is correct
11 Correct 12 ms 18800 KB Output is correct
12 Correct 13 ms 18772 KB Output is correct
13 Correct 11 ms 18760 KB Output is correct
14 Correct 12 ms 18772 KB Output is correct
15 Correct 11 ms 18788 KB Output is correct
16 Correct 11 ms 18772 KB Output is correct
17 Correct 12 ms 18772 KB Output is correct
18 Correct 11 ms 18772 KB Output is correct
19 Correct 11 ms 18772 KB Output is correct
20 Correct 11 ms 18724 KB Output is correct
21 Correct 13 ms 19028 KB Output is correct
22 Correct 13 ms 18864 KB Output is correct
23 Correct 12 ms 18872 KB Output is correct
24 Correct 12 ms 18796 KB Output is correct
25 Correct 16 ms 18900 KB Output is correct
26 Correct 14 ms 18900 KB Output is correct
27 Correct 14 ms 19020 KB Output is correct
28 Correct 16 ms 18932 KB Output is correct
29 Correct 15 ms 18900 KB Output is correct
30 Correct 15 ms 18956 KB Output is correct
31 Correct 15 ms 18900 KB Output is correct
32 Correct 15 ms 18900 KB Output is correct
33 Correct 14 ms 18900 KB Output is correct
34 Correct 15 ms 18924 KB Output is correct
35 Correct 14 ms 18900 KB Output is correct
36 Correct 15 ms 19020 KB Output is correct
37 Correct 14 ms 18928 KB Output is correct
38 Correct 14 ms 19004 KB Output is correct
39 Correct 14 ms 19024 KB Output is correct
40 Correct 14 ms 19080 KB Output is correct

Subtask #3
0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 18772 KB Output is correct
2 Correct 13 ms 18772 KB Output is correct
3 Correct 10 ms 18792 KB Output is correct
4 Correct 10 ms 18816 KB Output is correct
5 Correct 10 ms 18772 KB Output is correct
6 Correct 11 ms 18772 KB Output is correct
7 Correct 11 ms 18816 KB Output is correct
8 Correct 11 ms 18736 KB Output is correct
9 Correct 11 ms 18772 KB Output is correct
10 Correct 11 ms 18764 KB Output is correct
11 Correct 12 ms 18800 KB Output is correct
12 Correct 13 ms 18772 KB Output is correct
13 Correct 11 ms 18760 KB Output is correct
14 Correct 12 ms 18772 KB Output is correct
15 Correct 11 ms 18788 KB Output is correct
16 Correct 11 ms 18772 KB Output is correct
17 Correct 12 ms 18772 KB Output is correct
18 Correct 11 ms 18772 KB Output is correct
19 Correct 11 ms 18772 KB Output is correct
20 Correct 11 ms 18724 KB Output is correct
21 Correct 13 ms 19028 KB Output is correct
22 Correct 13 ms 18864 KB Output is correct
23 Correct 12 ms 18872 KB Output is correct
24 Correct 12 ms 18796 KB Output is correct
25 Correct 16 ms 18900 KB Output is correct
26 Correct 14 ms 18900 KB Output is correct
27 Correct 14 ms 19020 KB Output is correct
28 Correct 16 ms 18932 KB Output is correct
29 Correct 15 ms 18900 KB Output is correct
30 Correct 15 ms 18956 KB Output is correct
31 Correct 15 ms 18900 KB Output is correct
32 Correct 15 ms 18900 KB Output is correct
33 Correct 14 ms 18900 KB Output is correct
34 Correct 15 ms 18924 KB Output is correct
35 Correct 14 ms 18900 KB Output is correct
36 Correct 15 ms 19020 KB Output is correct
37 Correct 14 ms 18928 KB Output is correct
38 Correct 14 ms 19004 KB Output is correct
39 Correct 14 ms 19024 KB Output is correct
40 Correct 14 ms 19080 KB Output is correct
41 Correct 522 ms 43100 KB Output is correct
42 Correct 756 ms 32252 KB Output is correct
43 Correct 428 ms 31340 KB Output is correct
44 Correct 468 ms 31464 KB Output is correct
45 Correct 450 ms 31464 KB Output is correct
46 Execution timed out 1074 ms 45056 KB Time limit exceeded
47 Halted 0 ms 0 KB -