#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 "catinatree" #define pow ladsf const int N = 2000 + 5; const int mod = 1e9 + 7; const int oo = 1e9; struct Modint{ int x; Modint(){x = 0;} Modint(int _x){ x = (_x % mod + mod) % mod; } Modint operator + (const Modint &other) const{ return (x + other.x) % mod; } Modint operator - (const Modint &other) const{ return (x - other.x + mod) % mod; } Modint operator * (const Modint &other) const{ return (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 &t){ return os << t.x; } }; int n, k; int a[N], dp[N][N], f[N], pre[N][N], h[N]; vector<int> g[N]; void DFS(int u, int par){ FOA(v, g[u]){ if(v == par){ continue; } DFS(v, u); h[u] = max(h[v] + 1, h[u]); } FOR(i, 0, h[u]){ f[i] = 0; FOA(v, g[u]){ if(v == par){ continue; } f[i] += pre[v][max({0LL, i - 1, k - i})]; } } dp[u][0] = f[0] + 1; FOA(v, g[u]){ if(v == par){ continue; } FOR(i, 1, h[u]){ dp[u][i] = max(dp[u][i], f[i] + dp[v][i - 1] - pre[v][max({0LL, i - 1, k - i})]); } } FOD(i, h[u], 0){ pre[u][i] = max(dp[u][i], pre[u][i + 1]); } } signed main(){ quickly if(fopen(FILE".inp", "r")){ freopen(FILE".inp", "r", stdin); freopen(FILE".out", "w", stdout); } cin >> n >> k; --k; FOR(v, 1, n - 1){ int u; cin >> u; g[u].push_back(v); g[v].push_back(u); } DFS(0, -1); cout << pre[0][0]; }

catinatree.cpp: In function 'int main()':
catinatree.cpp:86:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   86 |                 freopen(FILE".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
catinatree.cpp:87:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   87 |                 freopen(FILE".out", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~