Consider the following two statements:
i. A hash function (these are often used for computing digital signatures) is an injective function.
ii. encryption technique such as DES performs a permutation on the elements of its input alphabet.
Which one of the following options is valid for the above two statements?

Consider a hash function that distributes keys uniformly. The hash table size is 20. After hashing of how many keys will the probability that any new key hashed collides with an existing one exceed 0.5.

Consider a hash table of size seven, with starting index zero, and a hash function (3x + 4)mod7. Assuming the hash table is initially empty, which of the following is the contents of the table when the sequence 1, 3, 8, 10 is inserted into the table using closed hashing? Note that ‘_’ denotes an empty location in the table.

Consider the following C program segment where CellNode represents a node in a binary tree:

struct CellNode 
{ 
     struct CellNOde *leftChild; 
     int element; 
     struct CellNode *rightChild; 
}; 

int GetValue(struct CellNode *ptr) 
{ 
     int value = 0; 
     if (ptr != NULL) 
     { 
       if ((ptr->leftChild == NULL) && 
        (ptr->rightChild == NULL)) 
       value = 1; 
       else 
         value = value + GetValue(ptr->leftChild) 
             + GetValue(ptr->rightChild); 
     } 
     return(value); 
} 

The value returned by GetValue() when a pointer to the root of a binary tree is passed as its argument is: