Submission #1307514

#	Time	Username	Problem	Language	Result	Execution time	Memory
1307514		edo	Cat in a tree (BOI17_catinatree)	C++20	100 / 100	66 ms	15468 KiB

catinatree

#include <bits/stdc++.h>

using namespace std;
using ll   = long long;
using vi   = vector<int>;
using vll  = vector<ll>;
using vvi  = vector<vi>;
using vvll = vector<vll>;
using pii  = pair<int,int>;
using pll  = pair<ll,ll>;
using ui    = unsigned int;
using ull   = unsigned long long;
using pui   = pair<ui,ui>;
using pull  = pair<ull,ull>;
using i128 = __int128_t;

template<typename T>
using vc = std::vector<T>;


#define YES cout << "YES\n"
#define NO  cout << "NO\n"
#define yes cout << "yes\n"
#define no  cout << "no\n"
#define Yes cout << "Yes\n"
#define No  cout << "No\n"

template<typename T> void sc(T &x) { cin >> x; }
template<typename T, typename U> void sc(pair<T,U> &p) { sc(p.first), sc(p.second); }
template<typename T> void sc(vector<T> &v) { for (auto &x : v) sc(x); }
template<typename... A> void sc(A&... a) { (sc(a), ...); }


template<typename T> void _pt(const T &x){cout << x;}
template<typename T, typename U> void _pt(const pair<T,U> &p){_pt(p.first); cout << ' '; _pt(p.second);}
template<typename T> void _pt(const vector<T> &v){bool f=1; for(auto &x:v){if(!f) cout<<' '; _pt(x); f=0;}}
template<typename... A> void pt(const A&... a){(_pt(a), ...);}


template<typename T, typename U> bool umin(T &a, const U &b) { return b < a ? (a = b, true) : false; }
template<typename T, typename U> bool umax(T &a, const U &b) { return b > a ? (a = b, true) : false; }
template<typename T> T maxel(const vector<T>& v){ return *max_element(v.begin(), v.end()); }
template<typename T> T minel(const vector<T>& v){ return *min_element(v.begin(), v.end()); }
template<typename T, int N> T maxel(T (&a)[N]) { return *max_element(a, a + N); }
template<typename T, int N> T minel(T (&a)[N]) { return *min_element(a, a + N); }


template<typename C, typename T> auto lb(C& c, const T& x){ return std::lower_bound(c.begin(), c.end(), x); }
template<typename C, typename T> auto ub(C& c, const T& x){ return std::upper_bound(c.begin(), c.end(), x); }

template<typename T> auto lb(std::set<T>& s, const T& x){ return s.lower_bound(x); }
template<typename T> auto ub(std::set<T>& s, const T& x){ return s.upper_bound(x); }
template<typename T> auto lb(const std::set<T>& s, const T& x){ return s.lower_bound(x); }
template<typename T> auto ub(const std::set<T>& s, const T& x){ return s.upper_bound(x); }

#define GET_MACRO(_1,_2,_3,_4,NAME,...) NAME
#define FOR1(n)            for (int i=0; i<(n); ++i)
#define FOR2(i,n)          for (int i=0; i<(n); ++i)
#define FOR3(i,l,r)        for (int i=(l); i<(r); ++i)
#define FOR4(i,l,r,k)      for (int i=(l); i<(r); i+=(k))
#define FOR(...)           GET_MACRO(__VA_ARGS__, FOR4, FOR3, FOR2, FOR1)(__VA_ARGS__)
#define ROF1(n)            for (int i=(n)-1; i>=0; --i)
#define ROF2(i,n)          for (int i=(n)-1; i>=0; --i)
#define ROF3(i,l,r)        for (int i=(r)-1; i>=(l); --i)
#define ROF4(i,l,r,k)      for (int i=(r)-1; i>=(l); i-=(k))
#define ROF(...)           GET_MACRO(__VA_ARGS__, ROF4, ROF3, ROF2, ROF1)(__VA_ARGS__)
#define all(c)   (c).begin(), (c).end()
#define allr(c)  (c).rbegin(), (c).rend()
#define eb       emplace_back
#define mp       make_pair
#define mt       make_tuple
#define fi       first
#define se       second
#define pb       push_back
#define trav(x,a) for (auto &x : (a))
#define sz(a) ((int)(a).size())
#define mem(a,v) memset(a, v, sizeof(a))
#define nl pt("\n")


int32_t main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, D;
    sc(n, D);
    vvi g(n);
    vi par(n);
    vi dep(n);
    vi ok(n);
    
    FOR(i, 1, n) {
        sc(par[i]);
        dep[i] = dep[par[i]] + 1;
        g[par[i]].pb(i);
        g[i].pb(par[i]);
    }

    vi order(n);
    iota(all(order), 0);
    sort(all(order), [&](int i, int j) {
        return dep[i] > dep[j];
    });
    
    auto update = [&](int x, auto&& self) {
        if(ok[x] == 1) return;
        int d = ok[x] - 1;
        trav(y, g[x]) {
            if(ok[y] < d) {
                ok[y] = d;
                self(y, self);
            }
        }
    };

    int ans = 0;
    FOR(o, n) {
        int i = order[o];
        if(!ok[i]) {
            ans++;
            ok[i] = D;
            update(i, update);
        }
    }

    pt(ans); nl;

    return 0;
}

• Subtask 1: 11 / 11
• Subtask 2: 40 / 40
• Subtask 3: 49 / 49