Longest consecutive sequence in Binary tree

PROBLEM :

Given a Binary Tree find the length of the longest path which comprises of nodes with consecutive values in increasing order. Every node is considered as a path of length 1.



Input :
The first line of the input contains a single integer T denoting the number of test cases. For each test a root node is given to the longestConsecutive function. The only input to the function is the root of the binary Tree.

Output:
For each test case output in a single line, find the length of the longest path of the binary tree.
If no such sequence is possible return -1.

Constraints:
1<=T<=50
1<=N<=50
Example:

Input:
2
2
1 2 L 1 3 R
5
10 20 L 10 30 R 20 40 L 20 60 R 30 90 L

Output:
2
-1

Explanation:
Test case 1:

           1
        /     \
     2        3

For the above test case the longest sequence is : 1 2 or 1 3

Test case 2:

            10
           /    \
        20     30
      /    \     /
  40      60 90

For the above test case no sequence is possible: -1

--------------------------------------------------------------------------------
SIMPLE c++ IMPLEMENTATION :
--------------------------------------------------------------------------------

/*
struct Node
{
int data;
Node *left, *right;
};
*/
// your task is tp complete this function
// function should return the length of the longestConsecutive
// sequence

void count(Node *,int ,int *) ;
int longestConsecutive(Node* root)
{
    int curr,ans ;
    curr=1 ;
    ans=0 ;
    count(root,curr,&ans) ;
    if(ans==1) return -1 ;
    return ans ;
}

void count(Node *root,int curr,int *ans)
{
    if(curr>(*ans))
        (*ans)=curr ;
       
    if(root==NULL) return ;
    if(root->left)
    if(root->data+1==root->left->data)
        count(root->left,curr+1,&(*ans)) ;
    else
        count(root->left,1,&(*ans)) ;
    if(root->right)  
    if(root->data+1==root->right->data)
        count(root->right,curr+1,&(*ans)) ;
    else
        count(root->right,1,&(*ans)) ;
}

---------------------------------------------------------------------------------

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