35 lines
695 B
C++
35 lines
695 B
C++
#include<cstdio>
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#include<algorithm>
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#include<vector>
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using namespace std;
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const int maxn=1005;
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int n,f[maxn],d[maxn],p[maxn],mark[maxn],res,ok[maxn],mark2[maxn];
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inline bool cmp(int a,int b) { return d[a]>d[b]; }
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int main()
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{
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#ifdef local
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freopen("pro.in","r",stdin);
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#endif
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scanf("%d",&n);
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f[1]=1; d[1]=1; p[1]=1;
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for(int i=2;i<=n;i++)
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{
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scanf("%d",&f[i]);
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d[i]=d[f[i]]+1;
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p[i]=i;
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}
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sort(p+1,p+1+n,cmp);
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for(int i=1;i<=n;i++)
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{
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int u=p[i];
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if(mark[u]||mark[f[u]]||mark[f[f[u]]]||ok[u]||mark2[f[u]]) { ok[u]=true; continue; }
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int v=f[f[u]];
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mark[v]=true;
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ok[u]=ok[f[u]]=ok[v]=ok[f[v]]=ok[f[f[v]]]=true;
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mark2[f[v]]=true;
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res++;
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}
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printf("%d\n",res);
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return 0;
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}
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