Find a pair with given target in BST

PROBLEM :

Given a Binary Search Tree and a target sum, write a function that returns true if there is a pair with sum equals to target sum, otherwise return false.

Input:
First line consists of T test cases. First line of every test case consists of N and target, denoting the number of elements in bst and target sum. Second line consists of elements of BST.

Output:
Return True if target sum pair is found else False.

Constraints:
1<=T<=100
1<=N<=100

Example:
Input:
2
7 10
1 2 3 4 5 6 7
7 33
15 10 20 8 12 16 25

Output:
1
1

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

/*Complete the function below
Node is as follows
struct node
{
    int val;
    struct node *left, *right;
};
*/

bool isPairPresent(struct node *root, int target)
{
    if(!root)
        return false ;
   
    stack<struct node*> sta1 ;
    stack<struct node*> sta2 ;
   
    bool done1,done2 ;
    done1=false ;
    done2=false ;
   
    int val1,val2 ;
    struct node *curr1, *curr2 ;
    curr1=root ;
    curr2=root ;
   
    while(true)
    {
        while(!done1)
        {
            if(curr1)
            {
                sta1.push(curr1) ;
                curr1=curr1->left ;
            }
            else
            {
                if(sta1.empty())
                    done1=true ;
                else
                {
                    curr1=sta1.top() ;
                    sta1.pop() ;
                    val1=curr1->val ;
                    curr1=curr1->right ;
                    done1=true ;
                }
            }
        }
       
        while(!done2)
        {
            if(curr2)
            {
                sta2.push(curr2) ;
                curr2=curr2->right ;
            }
            else
            {
                if(sta2.empty())
                    done2=true ;
                else
                {
                    curr2=sta2.top() ;
                    sta2.pop() ;
                    val2=curr2->val ;
                    curr2=curr2->left ;
                    done2=true ;
                }
            }
        }
     
        if((val1!=val2)&&((val1+val2)==target))
            return true ;
           
        else if((val1+val2)<target)
            done1=false ;
           
        else if((val1+val2)>target)
            done2=false ;
           
        if(val1>=val2)
            return false ;
    }
}

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