Algorithms
Sorting and searching, Recusrive algorithms and Backtracking, Greedy algorithms and complete search, Dynamic Programming, Graph Traversal, Shortest path algorithms like Bellman-ford and Dijkashtra, Topological Sorting, MST, Ranged queries. Number theory, Combinatorics, Game theory and Computational geometry.
Data structures
Basic structures like, Linked list, Stacks, Queue. Trees, BST, AVL Tree, Segment Tree, Fenwick Tree. Union-Find Disjoint sets Heap(Priority queue),Trie.
C++
Control Flow and branching, Loops, Pointers, Shared pointers, Arrays, Classes and structures, Functions, Namespaces and Exceptions, Operator overloading Templates, Iterators and STL.
Java
Basic structures like, Linked list, Stacks, Queue, Binary Search Trees, Heap(Priority queue),Trie.
Python
Basic structures like, Linked list, Stacks, Queue, Binary Search Trees, Heap(Priority queue),Trie.
HTML, CSS & JavaScript
Basic structures like, Linked list, Stacks, Queue, Binary Search Trees, Heap(Priority queue),Trie.