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Submission #562611

# Submission time Handle Problem Language Result Execution time Memory
562611 2022-05-14T20:09:15 Z anubhavdhar Cat in a tree (BOI17_catinatree) C++14
51 / 100
 1000 ms 12844 KB 
#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 = 640;
const ll LOGN = 18;
const ll INF = 1e18 + 1022;

int N, D, dis[MAXN], cat_cnt, mxdep[MAXN];
int dp[5][MAXN];
bool vis[MAXN];
vi g[MAXN];

void dfs(int a, int par)
{
	for(int b : g[a])
		if(b != par)
			dfs(b, a), dp[a][0] += dp[b][D-1];

	F0Rrev(i, D-1)
	{
		if(i == 0)
			break;
		int x = i;
		int y = max(i, D-i), sm = 0, mx = 0;
		for(int b : g[a])
			if(b != par)
				sm += dp[b][y-1], mx = max(dp[b][x-1] - dp[b][y-1], mx);
		dp[a][i] = sm + mx;
		if(i < D-1)
			dp[a][i] = max(dp[a][i], dp[a][i+1]);
	}

	dp[a][0] = max(dp[a][0], dp[a][1]);

	F0R(i, D)
	{
		// cout<<"dp["<<a-1<<"]["<<i<<"] = "<<dp[a][i]<<'\n';
		cat_cnt = max(cat_cnt, dp[a][i]);
	}
}

int dfs_find_end(int a, int p = -1){
	int ans = a;
	for(int b : g[a]){
		if(b != p && !vis[b]){
			dis[b] = 1 + dis[a];
			int t = dfs_find_end(b, a);
			if(dis[t] > dis[ans]){
				ans = t;
			}
		}
	}
	return ans;
}

void dfs_from_end(int a, vector<int>& V, int p = -1){
	for(int b : g[a]){
		if(b != p && !vis[b]){
			dis[b] = 1 + dis[a];
			cerr << "dis[" << b << "] = " << dis[b] << '\n';
			if(dis[b] < D){
				vis[b] = true;
				cerr << "blocking " << b << '\n';
			}else if(dis[b] == D){
				V.pb(b);
			}
			dfs_from_end(b, V, a);
		}
	}
}

int dfs_mxdep(int a, int p = -1){
	int t = a;
	for(int b : g[a]){
		if(b != p){
			dis[b] = dis[a] + 1;
			int y = dfs_mxdep(b, a);
			if(dis[t] < dis[y]){
				t = y;
			}
		}
	}
	mxdep[a] = dis[t];
	return t;
}

int cnt;
int dfs_cnt(int a, int p = -1, int dis = D + 1){
	for(int b : g[a]){
		if(b != p){
			dis = min(dis, 1 + dfs_cnt(b, a, dis + 1));
		}
	}
	if(dis >= D){
		// cerr << "dis for " << a << " is " << dis << "\n";
		++cnt;
		dis = 0;
	}
	return dis;
}

int solve(int a){
	dis[a] = 0;
	dfs_mxdep(a);
	F0Re(i, N){
		sort(all(g[i]), [&](int a, int b){return mxdep[a] > mxdep[b];});
	}
	cnt = 0;
	dfs_cnt(a);
	return cnt;
}

signed main()
{

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

	cin>>N>>D;



	cat_cnt = 1;

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

	// F0Re(i, N)
	// 	F0R(j, D)
	// 		dp[i][j] = (j==0) ? 1 : 0;

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

	if(D >= N)
	{
		cout<<"1\n";
		exit(0);
	}
	if(D == 1)
	{
		cout<<N<<'\n';
		exit(0);
	}
	// dbgLine;
	if(true || D >= ROOTN){
		F0Re(i, N){
			vis[i] = false;
		}
		int TTT = (N > 15000) ? 75 : 400;
		int ans = 1;
		while(TTT--){
			ans = max(ans, solve(1 + rand() % N));
		}
		cout << ans << '\n';
		exit(0);
	}

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

	// dfs(1, -1);

 
	// cerr << cat_cnt << '\n';
 
	return 0;
}

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 2 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 3 ms 4948 KB Output is correct
6 Correct 3 ms 4948 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4988 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 2 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 2 ms 4948 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 3 ms 4948 KB Output is correct
16 Correct 3 ms 4948 KB Output is correct
17 Correct 4 ms 4948 KB Output is correct
18 Correct 4 ms 4948 KB Output is correct
19 Correct 3 ms 4948 KB Output is correct
20 Correct 3 ms 4948 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 2 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 3 ms 4948 KB Output is correct
6 Correct 3 ms 4948 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4988 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 2 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 2 ms 4948 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 3 ms 4948 KB Output is correct
16 Correct 3 ms 4948 KB Output is correct
17 Correct 4 ms 4948 KB Output is correct
18 Correct 4 ms 4948 KB Output is correct
19 Correct 3 ms 4948 KB Output is correct
20 Correct 3 ms 4948 KB Output is correct
21 Correct 17 ms 5204 KB Output is correct
22 Correct 3 ms 4948 KB Output is correct
23 Correct 9 ms 5056 KB Output is correct
24 Correct 10 ms 5076 KB Output is correct
25 Correct 3 ms 4948 KB Output is correct
26 Correct 18 ms 5072 KB Output is correct
27 Correct 19 ms 5076 KB Output is correct
28 Correct 26 ms 5076 KB Output is correct
29 Correct 25 ms 5076 KB Output is correct
30 Correct 24 ms 5076 KB Output is correct
31 Correct 25 ms 5092 KB Output is correct
32 Correct 17 ms 5048 KB Output is correct
33 Correct 16 ms 5104 KB Output is correct
34 Correct 17 ms 5104 KB Output is correct
35 Correct 17 ms 5204 KB Output is correct
36 Correct 18 ms 5112 KB Output is correct
37 Correct 16 ms 5076 KB Output is correct
38 Correct 18 ms 5076 KB Output is correct
39 Correct 22 ms 5076 KB Output is correct
40 Correct 18 ms 5208 KB Output is correct

Subtask #3
0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 2 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 3 ms 4948 KB Output is correct
6 Correct 3 ms 4948 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4988 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 2 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 2 ms 4948 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 3 ms 4948 KB Output is correct
16 Correct 3 ms 4948 KB Output is correct
17 Correct 4 ms 4948 KB Output is correct
18 Correct 4 ms 4948 KB Output is correct
19 Correct 3 ms 4948 KB Output is correct
20 Correct 3 ms 4948 KB Output is correct
21 Correct 17 ms 5204 KB Output is correct
22 Correct 3 ms 4948 KB Output is correct
23 Correct 9 ms 5056 KB Output is correct
24 Correct 10 ms 5076 KB Output is correct
25 Correct 3 ms 4948 KB Output is correct
26 Correct 18 ms 5072 KB Output is correct
27 Correct 19 ms 5076 KB Output is correct
28 Correct 26 ms 5076 KB Output is correct
29 Correct 25 ms 5076 KB Output is correct
30 Correct 24 ms 5076 KB Output is correct
31 Correct 25 ms 5092 KB Output is correct
32 Correct 17 ms 5048 KB Output is correct
33 Correct 16 ms 5104 KB Output is correct
34 Correct 17 ms 5104 KB Output is correct
35 Correct 17 ms 5204 KB Output is correct
36 Correct 18 ms 5112 KB Output is correct
37 Correct 16 ms 5076 KB Output is correct
38 Correct 18 ms 5076 KB Output is correct
39 Correct 22 ms 5076 KB Output is correct
40 Correct 18 ms 5208 KB Output is correct
41 Execution timed out 1095 ms 12844 KB Time limit exceeded
42 Halted 0 ms 0 KB -