Collection of the codes of Coding Block and geeksforgeeks Courses : C++ Fundamentals & C++ STL & C++ Interview Preparation & Fork CPP & PPC-1
| S.No. | Question Name | Logic Used | Type | Date |
|---|---|---|---|---|
| 1 | Coin Change | lower_bound(STL) | Easy | 18 Oct 20 |
| 2 | Next Number Permutation | next_permutation(STL) | Easy | 18 Oct 20 |
| 3 | Max Activity Selection | greedy, pair container | Easy | 18 Oct 20 |
| 4 | Max Subarray Sum | div and conq, pair container | Medium | 19 Oct 20 |
| 5 | Key Sort Strings | string tokenizer, sort, pair container | Medium | 21 Oct 20 |
| 6 | Very Big Sort | string, sort, compare | Easy | 21 Oct 20 |
| 7 | Word Frequency | map, stringstream | Easy | 30 Oct 20 |
| 8 | Single occurence | bit, xor | Easy | 30 Oct 20 |
| 9 | count set bits | bit, &, >> | Easy | 30 Oct 20 |
| 10 | swap n bits binary | bit, &, >>, xor | Hard | 30 Oct 20 |
| 11 | subset sum = k | powerset, &, << | Medium | 31 Oct 20 |
| 12 | subsequences of given length | powerset, set bits, &, << | Hard | 31 Oct 20 |
| 13 | min chars del anagram | map, abs difference | Medium | 31 Oct 20 |
| 14 | pyramid pattern | for loop | Easy | 02 Nov 20 |
| 15 | square root | babylonian algo | Easy | 13 Nov 20 |
| 16 | 0,1 pattern | ternary operator, simple update | Easy | 13 Nov 20 |
| 17 | dec to octal | vector, for_each rev print | Easy | 13 Nov 20 |
| 18 | simple calculator | switch, signal 15 | Easy | 13 Nov 20 |
| 19 | Ramu travel cost | arrays | Easy | 14 Nov 20 |
| 20 | pair sum | arrays, 2 pointer approach | Easy | 14 Nov 20 |
| 21 | remove duplicate chars | arrays | Easy | 14 Nov 20 |
| 22 | increasing-decreasing subseq | arrays | Medium | 14 Nov 20 |
| 23 | strict split array | 2 vectors, sorting | Easy | 14 Nov 20 |
| 24 | vector for custom class | vectors, class, compare | Easy | 15 Nov 20 |
| 25 | pythagorean triplet | maths | Medium | 17 Nov 20 |
| 26 | trailing zeroes factorial | maths floor division | Easy | 20 Nov 20 |
| 27 | interval point membership | set of pair, upper_bound | Easy | 23 Nov 20 |
| 28 | substring overlapping occurrence | string find, string::npos | Easy | 01 Dec 20 |
| 29 | sum pivot with one swap | 2 maps and maths | Medium | 14 Dec 20 |
| 30 | second largest in array | 2 variables and swap | Easy | 14 Dec 20 |
| 31 | pair sum with duplicate elements | unordered_map, 2 pointer fails | Easy | 14 Dec 20 |
| 32 | min Steps to 1 | DP | Easy | 14 Dec 20 |
| 33 | distinct pair sum in array | map of pairs | Medium | 14 Dec 20 |
| 34 | rotate array clockwise | reverse 2 parts | Easy | 15 Dec 20 |
| 35 | rotate array counter-clockwise | Juggling Algo | Medium | 15 Dec 20 |
| 36 | spiral matrix print | 4 pointers, corner cases | Easy | 17 Dec 20 |
| 37 | median row-wise sorted matrix | binary search + upper_bound | Medium | 19 Dec 20 |
| 38 | kth smallest in row-col sorted matrix | binary search + staircase search | Medium | 20 Dec 20 |
| 39 | cyclic binary search | breakpoint parts + binary search | Easy | 22 Dec 20 |
| 40 | book allocation | monotonic search space | Medium | 23 Dec 20 |
| 41 | max element in window size = k | deque, sliding window technique | Hard | 27 Dec 20 |
| 42 | vertical order print of binary tree | queue, map, vector, recursion | Hard | 30 Dec 20 |
| 43 | next greater element, circular array | stack, traversal from right to left | Medium | 31 Dec 21 |
| 44 | k largest elements | minHeap of size k | Easy | 31 Dec 20 |
| 45 | merge k sorted arrays | minHeap and merge sort | Medium | 31 Dec 20 |
| 46 | merge k sorted linked lists | minHeap and merge sort | Medium | 01 Jan 21 |
| 47 | recursively reverse linked list | recursion and pointers | Medium | 09 Jan 21 |
| 48 | kth node from end linked list | fast, slow pointers | Easy | 09 Jan 21 |
| 49 | cycle detection in linked list | floyd, fast == slow | Medium | 09 Jan 21 |
| 50 | median of 2 sorted arrays | binary search, 4 variables | Hard | 10 Jan 21 |
| 51 | palindrome linked list | reverse from middle, compare | Easy | 13 Jan 21 |
| 52 | unique non-repeating chars substr | deque, sliding window | Easy | 20 Jan 21 |
| 53 | level order traversal of binary tree | height, recursion, kth print | Medium | 28 Jan 21 |
| 54 | right view of binary tree | NRL, new max level | Medium | 30 Jan 21 |
| 55 | tree nodes at distance K from target node | printAtLevel, ancestors U-turn | Hard | 31 Jan 21 |
| 56 | max path sum in Binary Tree | max branch_sum, max_sum from every node | Hard | 31 Jan 21 |
| 57 | flatten a tree into sorted linked list | postorder, return head and tail | Hard | 01 Feb 21 |
| 58 | Heap Sort | heapify, sort from right to left | Easy | 10 Feb 21 |
| 59 | max xor pair using TRIE | trie, left: 0, right: 0 | Medium | 13 Feb 21 |
| 60 | max subarray xor using TRIE | max xor pair in cumulative xor array | Medium | 13 Feb 21 |
| 61 | count of rectangles using set | set traversal, custom compare | Easy | 13 Feb 21 |
| 62 | Sort strings based on keys | stringstream, custom compare | Easy | 15 Feb 21 |
| 63 | Expedition SPOJ | sort, maxHeap, pick max fuel available | Hard | 20 Feb 21 |
| 64 | Unique Zero Triplet Sum | sorting, pair_sum 2 pointer approach | Medium | 24 Feb 21 |
| 65 | 4 Sum Unique | reduce to 2 sum, edge cases | Medium | 27 Feb 21 |
| 66 | fast power/ exponentiation | recursion, bit masking | Easy | 27 Feb 21 |
| 66 | K Sum generalized | recursion, pair sum using 2 pointers | Hard | 28 Feb 21 |
| 67 | minimize max diff in heights | min, max value, cannot be negative | Hard | 05 March 21 |
| 68 | Product array puzzle | suffix array, prefix variable | Easy | 05 March 21 |
| 69 | next permutation array | find req index, find swap val, reverse from i + 1 | Easy | 05 March 21 |
| 70 | Snakes and Ladders | BFS, calculate next positions | Hard | 18 March 21 |
| 71 | Segment Tree Sum Query | update, query, vector representation | Hard | 19 April 21 |
| 72 | Rare ASCII and Prime Factors | sum of digits of prime factors | Medium | 28 April 21 |