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Link List

9. Find whether a list is even or odd.
10. Reverse a link list with/without recursion.
11. Shuffle two link list of same size.
12. Merge two sorted link list.
13. Find whether two list are intersecting or not.
14. Detect a loop in link list.
15. Remove loop from link list.
16. Find the length of loop.
17. Find the kth element from end.
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  1. AshuMay 24, 2009 at 3:30 PM

    9. Find whether a list is even or odd.
    a) Keep counting.
    b) Use a bool for flag
    c) Without any variable
    int isOdd ( struct node *head )
    {
    Head = head->next;
    While ( head)
    {
    If ( head->next == NULL )
    Return 1;
    Head = head->next->next;
    }
    }
    10. Reverse a link list with/without recursion.
    Void reverselist( struct node *head )
    {
    Struct node *prev, *current, *temp;
    Prev = NULL;
    Current = head->next;
    While ( current )
    {
    Temp = current->next;
    Current->next = prev;
    Prev = current;
    Current = temp;
    }
    Head->next = prev;
    }

    11. Shuffle two link list of same size. If p and q are head pointers.
    Struct node *newhead = p;
    While (q )
    {
    Swap(&p->next, &q);
    P = p->next;
    }
    12. Merge two sorted link list.
    13. Find whether two list are intersecting or not.
    a) Use negation technique. Traverse list 1 and negate elements. Traverse list 2 and return first negated element.
    b) Hashtable: insert node in hashtable. If found collision return element.
    c) Length of list 1 = m length of list 2 = n. Traverse |m-n| element and then start comparing.
    14. Detect a loop in link list.
    a) Maintain a flag for each node visited. If you see any node already visited then a loop.
    b) use hashtable for nodes.
    c) Take two pointers. Increment first by one and another by two.
    Note: Application kernel programming and random number generator.

    15. Remove loop from link list.
    Use the loop detection approach and as soon as you know node->next is repeated, make it null.
    16. Find the length of loop.
    Use any of the above three approach and keep a counter until a node repeated.
    17. Find the kth element from end.
    a) Bruteforce: count the list nodes once and go for the (n-k) node next time.
    b) Maintain two pointer, both pointing to I and i-k node. So when pointer 1 point at n second one will point to n-k.

    ReplyDelete

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