# Status Problem video Level Completes Likes 243 Find two non-repeating numbers in an array in O(n) time and O(1) space Hard % 1 241 Separate even and odd integers in a given array Beginner % 0 238 Separate 0’s and 1’s in a given array Beginner % 0 223 Stock Single Sell Problem - Dynamic Programming - O(n) Medium % 2 221 Identifying Maximum Gain from Sequential Elements Medium % 0 217 Find two elements whose sum is closest to zero Medium % 1 216 Find the element which appears maximum number of times in the array Medium % 0 215 Find duplicates in an given array in O(n) time and O(1) space Medium % 0 213 Find the last repeating character in a given string Beginner % 0 212 Find the first non repeating character in a given string Beginner % 0 208 Dynamic Programming - Count all paths in 2D Matrix with Obstructions in it Medium % 1 205 Print All Diagonals of a given matrix Medium % 1 204 Dynamic Programming - Edit Distance Problem Hard % 2 202 Dynamic Programming - Box Stacking Problem Hard % 0 200 Dynamic Programming - Highway Billboard Problem Hard % 0 196 Double Threaded Binary Tree Complete Implementation Hard % 0 195 Single Threaded Binary Tree Complete Implementation Hard % 0 194 Introduction to Threaded Binary Tree Medium % 0 189 Convert BST to Greater Sum Tree Medium % 0 187 Reverse Alternative 'k' nodes in a Linked List. Medium % 0 Find two non-repeating numbers in an array in O(n) time and O(1) space Separate even and odd integers in a given array Separate 0’s and 1’s in a given array Stock Single Sell Problem - Dynamic Programming - O(n) Identifying Maximum Gain from Sequential Elements Find two elements whose sum is closest to zero Find the element which appears maximum number of times in the array Find duplicates in an given array in O(n) time and O(1) space Find the last repeating character in a given string Find the first non repeating character in a given string Dynamic Programming - Count all paths in 2D Matrix with Obstructions in it Print All Diagonals of a given matrix Dynamic Programming - Edit Distance Problem Dynamic Programming - Box Stacking Problem Dynamic Programming - Highway Billboard Problem Double Threaded Binary Tree Complete Implementation Single Threaded Binary Tree Complete Implementation Introduction to Threaded Binary Tree Convert BST to Greater Sum Tree Reverse Alternative 'k' nodes in a Linked List. 1 2 3 4 5 6 7 8