3143 sequential traversal of Binary Trees, 3143 Binary Trees

3143 sequential traversal of Binary Trees, 3143 Binary Trees

 

3143 sequential traversal of Binary Trees

 

Time Limit: 1 s space limit: 32000 KB title level: Silver Title Description Description

Returns the forward traversal of a binary tree.

Input description Input Description

The first line is an integer n, indicating the number of nodes in the tree.

The next n rows have two integers (L and R) in each row. The two integers Li and Ri in line I represent the left Son Number and the right son number of the node numbered I.

Output description Output Description

The output consists of three rows, namely, forward traversal, central traversal, and backward traversal. Numbers are separated by spaces.

Sample Input Sample Input

5

2 3

4 5

0 0

0 0

0 0

Sample output Sample Output

1 2 4 5 3

4 2 5 1 3

4 5 2 3 1

 1 #include<iostream> 2 using namespace std; 3 int root; 4 struct node 5 { 6     int parent; 7     int date; 8     int lchild; 9     int rchild;10 }a[101];11 void xianxu(int i)12 {13     cout<<i<<" ";14     if(a[i].lchild!=0)15     {16         xianxu(a[i].lchild);17     }18     if(a[i].rchild!=0)19     {20         xianxu(a[i].rchild);21     }22 }23 void zhongxu(int i)24 {25     if(a[i].lchild!=0)26     {27         zhongxu(a[i].lchild);28     }29     cout<<i<<" ";30     if(a[i].rchild!=0)31     {32         zhongxu(a[i].rchild);33     }34 }35 void houxu(int i)36 {37 38     if(a[i].lchild!=0)39     {40         houxu(a[i].lchild);41     }42     if(a[i].rchild!=0)43     {44         houxu(a[i].rchild);45     }46     cout<<i<<" ";47 }48 int main()49 {50     int n;51     cin>>n;52     for(int i=1;i<=n;i++)53     {54         cin>>a[i].lchild>>a[i].rchild;55         a[a[i].lchild].parent=i;56         a[a[i].rchild].parent=i;57     }58     for(int i=1;i<=n;i++)59     {60         if(a[i].parent==0)61         {62             root=i;63         }64     }65     xianxu(root);66     cout<<endl;67     zhongxu(root);68     cout<<endl;69     houxu(root);70     return 0;71 }