Submission #1437932

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Source Code Expand

#include<iostream>
#include<cstdio>
#include<vector>
#include<set>
using namespace std;
int a,b,c,i,j,k,ind[100009],p[100009],count;
int main(){
	cin>>a;
	for(i=2;i<=a;i++){
		cin>>b;
		ind[b]++;
		p[i]=b;
	}
	int vi[100009];
	for(i=1;i<=a;i++){
		vi[i]=1;
	}
	while(true){
		vector<int> q;
		for(j=2;j<=a;j++){
			if(ind[j]==0&&vi[p[j]]==1){
			//	ind[j]=-1;
			    vi[p[j]]=0;
				q.push_back(j);
			}
		}
		if(q.size()==0){
			cout<<count<<endl;
			return 0;
		}else{
		    count++;
		}
		for(j=0;j<q.size();j++){
		//	if(vi[p[q[j]]]){
				vi[p[q[j]]]=1;
				ind[p[q[j]]]--;
				ind[q[j]]=-1;
		//	}//else cout<<q[j]<<endl; 
		//	ind[p[q[j]]]--;
		}
	}
}

Submission Info

Judge Result