Submission #1939779

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Source Code Expand

#include <cstdio>
#include <cctype>
#include <algorithm>
#define repu(i,x,y) for (int i=x; i<=y; ++i)
#define repe(i,x) for (edge *i=fst[x]; i; i=i->nxt)
using namespace std;

int n,f[100100];
struct edge
{
    int v;
    edge *nxt;
} pool[100100],*tp=pool,*fst[100100];

int getint()
{
    char ch;
    while (!isdigit(ch=getchar()));
    int x=ch-'0';
    for (; isdigit(ch=getchar()); x=x*10+ch-'0');
    return x;
}

void dfs(int x)
{
    repe(i,x)
        dfs(i->v);
    static int a[100100];
    int tot=0;
    repe(i,x)
        a[++tot]=f[i->v];
    sort(a+1,a+1+tot);
    repu(i,1,tot)
        f[x]=max(f[x],a[i]+tot-i+1);
}

int main()
{
    n=getint();
    repu(i,2,n)
    {
        int x=getint();
        *tp=(edge){i,fst[x]},fst[x]=tp++;
    }
    dfs(1);
    printf("%d\n",f[1]);
    return 0;
}

Submission Info

Judge Result