Submission #256010

#	Time	Username	Problem	Language	Result	Execution time	Memory
256010		anubhavdhar	Cat in a tree (BOI17_catinatree)	C++14	11 / 100	4 ms	5120 KiB

catinatree

#include<bits/stdc++.h>

#define ll long long
#define pb push_back
#define mp make_pair
#define pii pair<int, int>
#define pll pair<ll, ll>
#define ff first 
#define ss second
#define vi vector<int>
#define vl vector<ll>
#define vii vector<pii>
#define vll vector<pll>
#define FOR(i,N) for(i=0;i<(N);++i)
#define FORe(i,N) for(i=1;i<=(N);++i)
#define FORr(i,a,b) for(i=(a);i<(b);++i)
#define FORrev(i,N) for(i=(N);i>=0;--i)
#define F0R(i,N) for(int i=0;i<(N);++i)
#define F0Re(i,N) for(int i=1;i<=(N);++i)
#define F0Rr(i,a,b) for(ll i=(a);i<(b);++i)
#define F0Rrev(i,N) for(int i=(N);i>=0;--i)
#define all(v) (v).begin(),(v).end()
#define dbgLine cerr<<" LINE : "<<__LINE__<<"\n"
#define ldd long double

using namespace std;

const int Alp = 26;
const int __PRECISION = 9;
const int inf = 1e9 + 8;

const ldd PI = acos(-1);
const ldd EPS = 1e-7;

const ll MOD = 1e9 + 7;
const ll MAXN = 2e5 + 5;
const ll ROOTN = 320;
const ll LOGN = 18;
const ll INF = 1e18 + 1022;

int N, D, dis[MAXN], cat_cnt, mxdep[MAXN];
vi g[MAXN];

int dfs_init(int a, int par, int dep)
{
    mxdep[a] = dep;
    for(int b : g[a])
        if(b != par)
            mxdep[a] = max(mxdep[a], 1 + dfs_init(b, a, dep + 1));
    return mxdep[a];
}

int dfs(int a, int par)
{
	// cout<<"in dfs("<<a<<','<<par<<")\n";
	F0R(i, (int)g[a].size())
		if(g[a][i] != par)
		{
			dis[g[a][i]] = dis[a] + 1;
			dis[a] = min(dis[a], dfs(g[a][i], a) + 1);
		}
	if(dis[a] >=  D)
	{
		dis[a] = 0;
		++cat_cnt;
        // cout<<"placed at node "<<a - 1<<'\n';
	}
	
	// cout<<"dis["<<a<<"] = "<<dis[a]<<'\n';

	return dis[a];
}

inline bool cmp(int a, int b)
{
    return mxdep[a] > mxdep[b];
}

signed main()
{

	/*
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	*/

	/*
	int test_case_number;
	cin>>test_case_number;
	while(test_case_number--)
		test_case();
	*/

	cin>>N>>D;

	cat_cnt = 0;

	F0Re(i, N)
		dis[i] = inf, mxdep[i] = 0;

	F0Re(i, N-1)
	{
		int j;
		cin>>j;
		g[i+1].pb(j+1);
		g[j+1].pb(i+1);
	}

    dfs_init(1, -1, 0);

    F0Re(i, N)
        sort(all(g[i]), cmp);

    dfs(1, -1);
 
 	cout<<cat_cnt<<'\n';

	return 0;
}

• Subtask 1: 11 / 11
• Subtask 2: 0 / 40
• Subtask 3: 0 / 49