# Status Problem Level Completes Likes 71 Maximum number edges to make Acyclic Undirected/Directed Graph Beginner % 0 72 Evaluation of Prefix Expressions (Polish Notation) | Set 2 Medium % 0 73 ZigZag OR Diagonal traversal in 2d array/Matrix using queue Medium % 0 74 Evaluation of Prefix Expressions (Polish Notation) | Set 1 Medium % 0 75 Minimum Boats Required to rescue people Medium % 0 76 Number of Islands Medium % 1 77 Minimum No of operations required to convert a given number to 1 - Integer Replacement Problem. Medium % 0 78 Evaluation of Postfix Expressions (Polish Postfix notation) | Set 2 Medium % 0 79 Evaluation of Postfix Expressions (Polish Postfix notation) | Set 1 Medium % 0 80 Find all the numbers in the range which has prime set bits. Beginner % 0 81 Check if Graph is Bipartite - Adjacency Matrix using Depth-First Search(DFS) Hard % 0 82 Check if Arithmetic Expression contains duplicate parenthesis Medium % 0 83 Round Price Problem Hard % 0 84 Smallest Number after Removing K digits Hard % 0 85 Determine the order of Tests when tests have dependencies on each other Medium % 0 86 Find the maximum number present in a String Beginner % 0 87 Reverse a Stack using recursion - In Place (Without using extra memory) Hard % 1 88 Convert Prefix to Postfix Expression Medium % 0 89 Convert Roman Number to Integer Beginner % 0 90 Sort a given stack - Using Temporary Stack Medium % 0 91 Convert Postfix to Prefix Expression Medium % 0 92 String to Integer (AtoI - ASCII to Integer) - Recursive Solution Medium % 0 93 Grouping of Anagrams Medium % 0 94 Longest contiguous character in a given String - O(N) Solution Beginner % 0 95 Convert Postfix to Infix Expression Medium % 0 96 String to Integer (AtoI - ASCII to Integer) Beginner % 1 97 Longest substring with at most two unique characters Medium % 0 98 Monotone Increasing Digits Medium % 1 99 Convert Infix to Prefix Expression Medium % 0 100 Max Flow Problem - Ford-Fulkerson Algorithm Hard % 0 101 Sum of all Unique elements in a given array Beginner % 0 102 Convert Infix to Postfix Expression Medium % 0 103 Find three smallest elements in a given array Beginner % 0 104 Evaluation of Infix expressions Medium % 0 105 Convert Prefix to Infix Expression Medium % 0 Maximum number edges to make Acyclic Undirected/Directed Graph Evaluation of Prefix Expressions (Polish Notation) | Set 2 ZigZag OR Diagonal traversal in 2d array/Matrix using queue Evaluation of Prefix Expressions (Polish Notation) | Set 1 Minimum Boats Required to rescue people Number of Islands Minimum No of operations required to convert a given number to 1 - Integer Replacement Problem. Evaluation of Postfix Expressions (Polish Postfix notation) | Set 2 Evaluation of Postfix Expressions (Polish Postfix notation) | Set 1 Find all the numbers in the range which has prime set bits. Check if Graph is Bipartite - Adjacency Matrix using Depth-First Search(DFS) Check if Arithmetic Expression contains duplicate parenthesis Round Price Problem Smallest Number after Removing K digits Determine the order of Tests when tests have dependencies on each other Find the maximum number present in a String Reverse a Stack using recursion - In Place (Without using extra memory) Convert Prefix to Postfix Expression Convert Roman Number to Integer Sort a given stack - Using Temporary Stack Convert Postfix to Prefix Expression String to Integer (AtoI - ASCII to Integer) - Recursive Solution Grouping of Anagrams Longest contiguous character in a given String - O(N) Solution Convert Postfix to Infix Expression String to Integer (AtoI - ASCII to Integer) Longest substring with at most two unique characters Monotone Increasing Digits Convert Infix to Prefix Expression Max Flow Problem - Ford-Fulkerson Algorithm Sum of all Unique elements in a given array Convert Infix to Postfix Expression Find three smallest elements in a given array Evaluation of Infix expressions Convert Prefix to Infix Expression 1 2 3 4 5 6 7 8 9