zoj 3805 Machine

http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=5337

 1 #include <cstdio>

 2 #include <cstring>

 3 #include <vector>

 4 #include <algorithm>

 5 using namespace std;

 6 

 7 vector<int>g[1001100];

 8 int a[100101];

 9 int in[100101];

10 int n;

11 int dfs(int u)

12 {

13     int c,x;

14     if(in[u]==0) return 1;

15     if(in[u]==1)

16     {

17         c=dfs(g[u][0]);

18         return c;

19     }

20     else

21     {

22         c=dfs(g[u][0]);

23         x=dfs(g[u][1]);

24         if(c!=x) return max(x,c);

25         else return c+1;

26     }

27 

28 }

29 

30 int main()

31 {

32    while(scanf("%d",&n)!=EOF)

33    {

34        for(int i=1; i<=n; i++)

35        {

36            g[i].clear();

37        }

38        memset(in,0,sizeof(in));

39        for(int i=1; i<=n-1; i++)

40        {

41            scanf("%d",&a[i]);

42            g[a[i]].push_back(i+1);

43            in[a[i]]++;

44        }

45        printf("%d\n",dfs(1));

46    }

47    return 0;

48 }

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