hariharanragothaman / cppmaster Goto Github PK

• Array: Flattening
• Array: Consecutive Combo
• Array: Continuous Subsegment Counts
• Binary Tree: Basics & Traversals
• Binary Tree: Check if Left and Right subtrees are Mirror Images / Symmetric
• Binary Tree: LCA (Basic Recursion)
• DisjointSet Union
• Hashmap: Merging Hashmaps
• Hashmap: Sort
• Hashmap: Tuple to Hashmap
• Hashmap: Generic Stuff
• LinkedList: SLL
• MultiMap
• MultiSet
• OrderedSet
• Range Query: Prefix Sum
• Range Query: FenwickTree
• Range Query: Segment Tree (Min/Max/Sum)
• Range Query: Segment Tree (Offset)
• Trie: Template1
• Trie: Template2

• auto
• casts
• constructDestruct
• lambdas
• move_semantics
• multithreading
• smart pointers
• Templates
• Vector Hacks
• String Hacks
• Generic OOPS

• Check Bi-Partite
• Check if Cycle Exists
• Check Cycle without recursion - Brent's Algorithm
• Check if we can visit all nodes (DFS)
• Count number of connected components in an undirected graph
• Djikstra (Using Heap)
• Find Shortest Path from Source to Target
• Find Path b/w Source & Target - Single Parent
• Find minimum vertices to reach all nodes
• Topological Sort
• BFS & DFS

• Check Palindrome
• Change to Lower
• Check if s is subsequence of t
• Generate all substrings O(n^2)
• Hashing (Rolling Hash)
• KMP
• Longest Common Substring (LCS)
• Longest Increasing Subsequence (LIS)
• Rabin Karp
• Rolling Hash - Find duplicates in a list of strings
• Rolling Hash - Count distinct substrings in a string

• Prime Check
• Get Factors
• Bitwise Tricks
• Reverse Integer
• GCD & LCM
• 2D Matrices Tricks
• Combinatorics

• Binary Search

• Decorators Basics
• Itertools - Useful tricks

• FastIO
• Get Stack Depth
• Increase Recursion Limit

Something to remember is many STL functions can be applied for several containers. Remember this. Eg: count() can be used for vector and strings like Counter() in python.
Like that find_end, find_first_of can be applied.

Some key things to remember when starting off:

1. begin() and end() are used for iterators

2. front() and back() are used for - looking up

3. unordered_map is faster

4. map sorts by key by default

5. iterator to index -> it - v.begin() instead of std::distance()
   https://stackoverflow.com/questions/2152986/what-is-the-most-effective-way-to-get-the-index-of-an-iterator-of-an-stdvector

6. Rememeber these 2 styles Parsing through a vector and comparing each element

Case1 : Here you go with the iterator approach - and this is how you compare.

for (auto it = words.begin(); it != words.end(); ++it){
            if ((*it).compare(word1) == 0)
               pos = it - words.begin()

Case 2: You go with the routine approach:

    for(int i = 0; i < words.size(); i++) {
        if (words[i] == word1)

7. There are 25 prime numbers from 1 to 100.

8. Something to remember here is that:
   all these functions - take iterators as I/P's.
   But iterators are more like pointers and they can be incremented or decremented

9. So this concept called ptr is being used here, so that it can be re-used everywhere else. Guess that's this has been implemented in C++ example is: count() - for compile time polymorphism Like templates