#include <bits/stdc++.h> using namespace std; #define int long long #define FOR(I, L, R) for(int I(L) ; I <= (int)R ; ++I) #define FOD(I, R, L) for(int I(R) ; I >= (int)L ; --I) #define FOA(I, A) for(auto &I : A) #define print(A,L,R) FOR(OK, L, R){if(A[OK]<=-oo / 10||A[OK]>=oo)cout<<"- ";else cout<<A[OK]<<' ';}cout<<'\n'; #define prints(A) FOA(OK, A){cout<<OK<<' ';}cout << '\n'; #define printz(A,L,R) FOR(OK, 1, L){FOR(KO, 0, R){if(A[OK][KO]>-oo&&A[OK][KO]<oo)cout<<A[OK][KO]<<' ';else cout << "- ";} cout << '\n';}cout << '\n'; #define fs first #define sd second #define ii pair<int,int> #define iii pair<int, ii> #define all(A) A.begin(), A.end() #define quickly ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); #define FILE "FILE" const int N = 2e5 + 5; const int SQRT = 320; const int mod = 1e9 + 9999; const int oo = 1e18; struct Modint{ int x; Modint(){x = 0;} Modint(int _x){x = (_x + mod) % mod;} Modint operator + (const Modint &other) const{ return Modint((x + other.x) % mod); } Modint operator - (const Modint &other) const{ return Modint((x - other.x + mod) % mod); } Modint operator * (const Modint &other) const{ return Modint((1LL * x * other.x) % mod); } void operator += (const Modint &other) { *this = *this + other; } void operator -= (const Modint &other) { *this = *this - other; } void operator *= (const Modint &other) { *this = *this * other; } friend ostream& operator << (ostream& os, const Modint &other){ return os << other.x; } }; int n, k; vector<int> g[N]; namespace SubtaskSQRT{ static const int M = 1005 + 5; static int dp[M][M], pre[M][M], h[M]; static int opt[N]; void DFS(int u, int par){ FOA(v, g[u]){ DFS(v, u); h[u] = max(h[u], h[v] + 1); } FOR(i, 0, k) opt[i] = -oo; FOR(i, 0, h[u]){ opt[i] = 0; FOA(v, g[u]){ opt[i] += pre[v][max({0LL, i - 1, k - i - 1})]; } } dp[u][0] = max(1LL, opt[k] + 1); FOD(i, h[u], 1){ FOA(v, g[u]){ dp[u][i] = max(dp[u][i], dp[v][i - 1] + opt[i] - pre[v][max({0LL, i - 1, k - i - 1})]); } } pre[u][0] = dp[u][0]; FOR(i, 1, h[u]){ pre[u][i] = max(dp[u][i], pre[u][i - 1]); } } void solve(){ memset(dp, -0x3f, sizeof dp); memset(pre, -0x3f, sizeof pre); DFS(1, -1); int ans = 0; FOR(i, 0, n){ ans = max(ans, dp[1][i]); } cout << ans; } } signed main(){ quickly if(fopen(FILE".inp", "r")){ freopen(FILE".inp", "r", stdin); freopen(FILE".out", "w", stdout); } cin >> n >> k; FOR(i, 2, n){ int x; cin >> x; g[x + 1].push_back(i); } if(k > n){ cout << 1; } else if(n <= 1005){ SubtaskSQRT::solve(); } }

catinatree.cpp: In function 'int main()':
catinatree.cpp:101:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  101 |                 freopen(FILE".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
catinatree.cpp:102:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  102 |                 freopen(FILE".out", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~