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  1. //Initial Template for C++
  2. #include <bits/stdc++.h>
  3. using namespace std;
  4.  
  5. struct Node
  6. {
  7. 	int data;
  8. 	struct Node *left, *right;
  9. };
  10.  
  11. Node* newNode(int data)
  12. {
  13. 	Node *temp = new Node;
  14. 	temp->data = data;
  15. 	temp->left = temp->right = NULL;
  16. 	return temp;
  17. }
  18.  
  19. void printInorder(Node* node)
  20. {
  21. 	if (node == NULL)
  22. 		return;
  23. 	printInorder(node->left);
  24. 	cout<<node->data<<" ";
  25. 	printInorder(node->right);
  26. }
  27.  
  28. void pairwiseSwap(Node **root)
  29. {
  30.     // code here
  31.     Node **firstPtr, **secondPtr;
  32.     int count = 0;
  33.     if ((*root) == NULL)
  34.         return;
  35.     if ((*root)->left == NULL && (*root)->right == NULL)
  36.     {
  37.         count++;
  38.         if (count%2)
  39.             swap(firstPtr, secondPtr);
  40.         else
  41.         	firstPtr = secondPtr;
  42.  
  43.     }
  44.     pairwiseSwap(&(*root)->left);
  45.     pairwiseSwap(&(*root)->right);
  46. }
  47.  
  48. int main()
  49. {
  50.   int t;
  51.   scanf("%d", &t);
  52.   while (t--)
  53.   {
  54.      map<int, Node*> m;
  55.      int n;
  56.      scanf("%d",&n);
  57.      struct Node *root = NULL;
  58.      struct Node *child;
  59.      while (n--)
  60.      {
  61.         Node *parent;
  62.         char lr;
  63.         int n1, n2;
  64.         scanf("%d %d %c", &n1, &n2, &lr);
  65.         if (m.find(n1) == m.end())
  66.         {
  67.            parent = newNode(n1);
  68.            m[n1] = parent;
  69.            if (root == NULL)
  70.              root = parent;
  71.         }
  72.         else
  73.            parent = m[n1];
  74.         child = newNode(n2);
  75.         if (lr == 'L')
  76.           parent->left = child;
  77.         else
  78.           parent->right = child;
  79.         m[n2]  = child;
  80.      }
  81.      pairwiseSwap(&root);
  82.      printInorder(root);
  83.      cout<<" ";
  84.   }
  85.   return 0;
  86. }
Success #stdin #stdout 0s 15240KB
comments (?)
stdin
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2
2
1 2 R 1 3 L
4
10 20 L 10 30 R 20 40 L 20 60 R
stdout
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3 1 2  40 20 60 10 30
https://ideone.com/Q59Fsj
language:
C++ (gcc 8.3)
created:
4 years ago
visibility:
public

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