Submission #1751454

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Source Code Expand

#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,a,b) for(int i=(a);i>=(b);i--)
#define forE(i,x) for(int i=head[x];i!=-1;i=ne[i])
using namespace std;
typedef long long i64;
typedef unsigned long long u64;
typedef unsigned u32;
typedef pair<int,int> pin;
#define mk(a,b) make_pair(a,b)
#define lowbit(x) ((x)&(-(x)))
#define sqr(a) ((a)*(a))
#define clr(a) (memset((a),0,sizeof(a)))
#define ls ((x)<<1)
#define rs (((x)<<1)|1)
#define mid (((l)+(r))>>1)
#define pb push_back
#define w1 first
#define w2 second
inline void read(int &x){
	x=0;int f=1;char ch=getchar();
	while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
	while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
	x*=f;
}
inline void judge(){
	freopen("in.txt","r",stdin);
	freopen("out.txt","w",stdout);
}
/*******************************head*******************************/
const int maxn=100005;
int cnt[maxn],n,a[maxn],vis[maxn];
vector<int> bl[maxn];
inline bool cmp(int x,int y){
	return a[x]>a[y];
}
inline int calc(int x){
	if(vis[x])return a[x];vis[x]=1;
	for(int v:bl[x])calc(v);
	sort(bl[x].begin(),bl[x].end(),cmp);
	int nowcnt=0;
	for(int v:bl[x]){
		nowcnt++;
		a[x]=max(a[x],nowcnt+a[v]);
	}
	return a[x];
}
int main(){
	read(n);
	rep(i,1,n-1){
		int x;read(x);cnt[x]++;
		bl[x].pb(i+1);
	}int ans=0;
	rep(i,1,n)ans=max(ans,calc(i));
	cout<<ans<<endl;
	return 0;
}

Submission Info

Judge Result