# Status Problem Level Completes Likes 71 Dijkstra Algorithm Implementation – TreeSet and Pair Class Hard % 0 72 Check if Given Number is power of 2. Beginner % 1 73 Rotate the given array in cycles Beginner % 0 74 Heap Sort – Java Implementation Medium % 0 75 Find no of reverse pairs in an array which is sorted in two parts in O(N) Medium % 1 76 Get the Sum of Digits in a number till it become a single digit Medium % 0 77 Check if given number is Prime - O(√N) Solution – Java Program Medium % 0 78 Fizz Buzz Challenge - Java Implementation Beginner % 0 79 Graph – Detect Cycle in an Undirected Graph using DFS Medium % 0 80 Graph – Detect Cycle in a Directed Graph Medium % 1 81 Graph – Software Installation Problem Medium % 0 82 Topological Sort Medium % 1 83 Sliding Window Algorithm (Track the maximum of each subarray of size k) Hard % 0 84 Print all sub sequences of a given array Hard % 0 85 Remove Duplicates from a string Medium % 0 86 Dynamic programming – Minimum Jumps to reach to end Hard % 0 87 Find three elements in an array that sum to a given value Beginner % 0 88 Majority Element- Boyer–Moore majority vote algorithm Medium % 0 89 Check whether the given number is a perfect square Beginner % 0 90 Find the Index from which 0 starts Beginner % 0 91 Find the only element in array which appears only once Beginner % 1 92 Algorithm to calculate power(k,n). Beginner % 1 93 Find the two repeating elements in a given array | 6 Approaches Medium % 1 94 Find two elements whose sum is closest to zero Medium % 1 95 Find duplicates in an given array in O(n) time and O(1) extra space. Medium % 0 96 Find the last non repeating character in a given string. Beginner % 0 97 Find the last repeating character in a given string. Beginner % 0 98 Find the first non repeating character in a given string Beginner % 0 99 Find the first repeating character in a given string Beginner % 0 100 Print All Diagonals of a given matrix Medium % 1 101 Kadane's Algorithm - Maximum Subarray Problem Medium % 1 102 Implement Stack Using Linked List Beginner % 0 103 Reverse a Linked List in groups of given size 'K' Medium % 0 104 Find the Kth Smallest/Largest Element in an Array Beginner % 0 105 Dynamic Programming - Stairs Climbing Puzzle Beginner % 1 Dijkstra Algorithm Implementation – TreeSet and Pair Class Check if Given Number is power of 2. Rotate the given array in cycles Heap Sort – Java Implementation Find no of reverse pairs in an array which is sorted in two parts in O(N) Get the Sum of Digits in a number till it become a single digit Check if given number is Prime - O(√N) Solution – Java Program Fizz Buzz Challenge - Java Implementation Graph – Detect Cycle in an Undirected Graph using DFS Graph – Detect Cycle in a Directed Graph Graph – Software Installation Problem Topological Sort Sliding Window Algorithm (Track the maximum of each subarray of size k) Print all sub sequences of a given array Remove Duplicates from a string Dynamic programming – Minimum Jumps to reach to end Find three elements in an array that sum to a given value Majority Element- Boyer–Moore majority vote algorithm Check whether the given number is a perfect square Find the Index from which 0 starts Find the only element in array which appears only once Algorithm to calculate power(k,n). Find the two repeating elements in a given array | 6 Approaches Find two elements whose sum is closest to zero Find duplicates in an given array in O(n) time and O(1) extra space. Find the last non repeating character in a given string. Find the last repeating character in a given string. Find the first non repeating character in a given string Find the first repeating character in a given string Print All Diagonals of a given matrix Kadane's Algorithm - Maximum Subarray Problem Implement Stack Using Linked List Reverse a Linked List in groups of given size 'K' Find the Kth Smallest/Largest Element in an Array Dynamic Programming - Stairs Climbing Puzzle 1 2 3 4