Quick Interview Practice I

I did a few mock interview questions with my roommate today. Here’s some of what we went through.

#1 Find the height of a tree

#1 Find the height of a tree
 
 struct Node
 {
     Node* left;
     Node* right;
     
     int data;
 }

int FindHeight(Node* head, int depth)
{
    if( head == NULL ) 
        reutrn depth;
        
    return max(FindHeight(head->left, depth + 1), FindHeight(head->right, depth + 1));
}

#2 Find the largest palindrome product of three digits [100, 999].

//#2 Find the largest palindrome product of 3 digits
// 
 bool IsPalindrome(int value)
 {
     string stringVal;
     atoi(value, stringVal);
     
     for(int a = 0, b = stringVal.size(); a != b; ++a, --b)
     {
         if(stringVal[a] != stringVal[b])
             return false;
     }
     
     return true;
 }
 
 int FindLargestPalindrome()
 {
     // [100, 999]
     for(int a = 999; a > 0; --a)
     {
         for(int b = 999; b > 0; --b)
         {
           int result = a*b;
           if(IsPalindrome(result))
               reutrn result;
         }
     }
     
     return -1;
 }
 

# Detect rectangle overlap in one check.

 // #3 Detect rectangle overlap in one check

 struct Point
 {
     int x;
     int y;
 };
 
 struct Rect
 {
     Point TopLeft;
     Point BottomRight;
 };
 
 bool IsOverlapped(Rect r1, Rect r2)
 {     
     // r1 intersects with r2
     if(r1.BottomRight.x > r2.TopLeft.x &&
        r1.TopLeft.x < r2.BottomRight.x &&
        r1.BottomRight.y < r2.TopLeft.y &&
        r1.TopLeft.y > r2.BottomRight.y)
            return true;        
 }

#4 Return the middle element of a singly linked list in one pass

#4 Return the middle element of a singly linked list in one pass
Node* MiddleElement(Node* head)
{
  Node* step1 = head;
  Node* step2 = head;

  while(step2 != NULL)
  {
    step1 = step1->next;

    if(step2->next)             // This check is to avoid over stepping the null termination
      step2 = step2->next->next;
    else
      step2 = step2->next;
  {

  return step1;
}