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| #include <bits/stdc++.h>
using namespace std;
const double eps = 1e-10;
const double pi = 3.1415926535897932384626433832795;
const double eln = 2.718281828459045235360287471352;
#define f(i, a, b) for (int i = a; i <= b; i++)
#define scan(x) scanf("%d", &x)
#define mp make_pair
#define pb push_back
#define lowbit(x) (x&(-x))
#define fi first
#define se second
#define SZ(x) int((x).size())
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define summ(a) (accumulate(all(a), 0ll))
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef vector<int> vi;
using ll=long long;
ll tt,n,k,fa[(int)2e5+9],cnt;
vi g[(int)2e5+9];
ll dfs(int u,int fa,int dep,ll x){
ll res=0;
for(auto it:g[u]){
res=max(dfs(it,u,dep+1,x),res);
}
res+=1;
if(res>=x&&fa!=1)cnt+=1,res=0;
return res;
}
bool check(ll x){
cnt=0;
dfs(1,1,0,x);
return cnt<=k;
}
void solve(){
cin>>n>>k;
for(int i=1;i<=n;++i)g[i].clear();
for(int i=2;i<=n;++i)cin>>fa[i],g[fa[i]].push_back(i);
ll l=1,r=n-1;
while(l<r){
ll mid=(l+r)>>1;
if(check(mid))r=mid;
else l=mid+1;
}
cout<<l<<'\n';
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(0);
cin>>tt;
f(sb,1,tt)solve();
return 0;
}
|