25. Linked list-2 : Insertion | deletion

 

remember to include edge cases in ques of linked list...
--------------------------------------------------------------------------------------------------------------------------

DELETING Head-

head ko temp mein daalke temp ko free kardo & head ko next pe move krdo

-----------------------------------------------------------------------------------------------------------------------------

DELETING Tail-

pointer ko 2nd last element pe le jaake is temp pointer mein last element store karlo aur 2nd last ka next null krke temp ko free krdo
--------------------------------------------------------------------------------------------------------------------------
DELETING kth elmt-

counter Lagake (k-1)th node pe pahunch jaao & kaam krdo
-----------------------------------------------------------------------------------------------------------------------------

Deleting given elmt-⭐

------------------------------------------------------------------------------------------------------------------------

Inserting at start or at end-

------------------------------------------------------------------------------------------------------------------------
Inserting at kth pos-⭐


----------------------------------------------------------------------------------------------------------------------------
 Inserting before element X:

----------------------------------------------------------------------------------------------------------------------------

Comments

Post a Comment

Popular posts from this blog

30.) DP on subsequences

Image
Subset sum = target✅⭐ Partition equal subset sum✅ Partition array into 2 subsets with min abs [sum(v1)-sum(v2) ]✅ Count subsets with sum k✅⭐ Count partitions with given diff✅ target sum✅ 0/1 knapsack✅⭐ min coins✅---->count min coins to be taken coin change-2--->count n(ways) of taking coins⭐✅ unbounded knapsack✅ rod cutting problem✅ ----------------------------------------------------------------------------------------------------------------------------- 2 ways to generate all subsequences- Power Set, or Recursion subset means subsequence in dsa ----------------------------------------------------------------------------------------------------------------------------- 1. Target Sum- QUES- return true if there exists a subset with sum equal to the target in the array... Soln assuming all array elements are positive  here f(n-1,target) will tell if there's a subsequence till n-1 index with sum = target 1.) RECURSIVE SOLN-        ( time: 2^n    ...
Read more

19. Strings (LB)

Image
Character Array- 1. We use  1d character array  to simulate strings, e.g., char ch[10]; cin>>ch; 2. string ends with '\0' 3. cin with string works only if till space, tab or new line is absent in input... 4. work with character array just like a normal array, here only datatype is changed to char, else wise it is just an array -------------------------------------------- 5. In-Built functions- - int n = strlen(ch)   - strcmp(s1,s2)            // gives 0 if both strings are equal  - strcpy(dest,source)   // copies a string from dest to source -------------------------------------------- ----------------------------------------------------------------------------------------------------------------------------- STRING- It is a C++ STL 1. has dynamic size (can dynamically increase size when needed) 2. null terminator (\0) NOT required 3. Has built-in functions : - return s.size() - return s == "hello" - return s + "wor...
Read more

32. Binary Trees-2 (bfs/dfs med problems)

Image
Medium problems- more imp---------------------- height            ✅ diameter        ✅ max path sum✅⭐ Height Balanced BT check✅ identical BT check✅ Symmetric BT check✅⭐ medium imp------------------- Zig Zag traversal✅ Boundary Traversal✅ Vertical order Traversal✅⭐ less imp---------------------------- Top view ✅⭐ Bottom view✅ Right/ Left view✅ ----------------------------------------------------------------------------------------------------------------------------- 1. Max Depth of BT- height(tree)  =    n(nodes) in longest path from top to bottom time-N          space-N ----------------------------------------------------------------------------------------------------------------------------- 2. Balanced BT check- it means for every   node:      [ H(left) - H(right) ] <=1 Brute-          time: O(n^2) -------------------------------------------...
Read more