24. Linked List-1: construction | traversal

Basics-

1) Intro to LL-

in a LL, elmts are not in contigous locations
size can be changed at any moment...
example of linked list usage is a browser's fwd & back btn...

LL consists of head and tail
each elmt stores 2 things- data & a pointer to the next elmt

elements of a 1D LL only have a next ptr, while 2D LL have both next & prvs ptr...   
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2) Pointers-


in 32-bit sys pointer takes 4 bytes
in 64-bit sys pointer takes 8 bytes
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3) Struct-

a self defined data type...
It needs a constructor to initialize things at first.
if we use class keyword instead of struct we can use oops concepts as well

y wala method prefer krenge hum...
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4) Constructors

special functions which are used to initialize objects of the classes
we can have multiple constructors
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1. Converting array to LL- O(n)
for every element-
1. create new node pointing to null
2. point prev node to curr node
3. move prev node to curr node

mover node used to move & temp node used to create & store new nodes

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2. Traversal-
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3. Length of linked list-

traversal mein ek counter lagado cout se pehle
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4. Searching- O(n)
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