Problems # Status Problem Level Completes Likes 141 Check if Arithmetic Expression contains duplicate parenthesis Medium % 0 142 Introduction to Bipartite Graphs OR Bigraphs Medium % 1 143 Reverse the Directed Graph Beginner % 0 144 Round Price Problem Hard % 0 145 Smallest Number after Removing K digits Hard % 0 146 Find Third Smallest elements in a given array Beginner % 0 147 Determine the order of Tests when tests have dependencies on each other Medium % 0 148 Implement Graph Using Map - Java Medium % 0 149 Find the maximum number present in a String Beginner % 0 150 Count number of subgraphs in a given graph Beginner % 0 151 Reverse a Stack using recursion - In Place (Without using extra memory) Hard % 0 152 Check if given an edge is a bridge in the graph Medium % 0 153 Convert Prefix to Postfix Expression Medium % 0 154 Convert Roman Number to Integer Beginner % 0 155 Sort a given stack - Using Temporary Stack Medium % 0 156 Convert Postfix to Prefix Expression Medium % 0 157 Convert Integer to Roman Medium % 0 158 String to Integer (AtoI - ASCII to Integer) - Recursive Solution Medium % 0 159 Grouping of Anagrams Medium % 0 160 Print Processes and its messages from a given log file Medium % 0 161 Linear Search vs Binary Search Beginner % 0 162 K-Means Algorithm Hard % 0 163 Count the number of nodes in a given binary tree Beginner % 1 164 Sieve of Eratosthenes - Find all Prime Numbers less than equal to N | Set 2 Medium % 0 165 Longest contiguous character in a given String - O(N) Solution Beginner % 0 166 Convert Postfix to Infix Expression Medium % 0 167 Collatz Conjecture - Steps to transform Number to 1 Beginner % 0 168 String to Integer (AtoI - ASCII to Integer) Beginner % 0 169 Find all Prime Numbers less than equal to N | Set 1 Beginner % 0 170 Longest substring with at most two unique characters Medium % 0 171 Monotone Increasing Digits Medium % 0 172 Convert Infix to Prefix Expression Medium % 0 173 Find third largest element in a given array Beginner % 0 174 Find duplicates Characters in the given String Beginner % 0 175 Max Flow Problem - Ford-Fulkerson Algorithm Hard % 0 Check if Arithmetic Expression contains duplicate parenthesis Introduction to Bipartite Graphs OR Bigraphs Reverse the Directed Graph Round Price Problem Smallest Number after Removing K digits Find Third Smallest elements in a given array Determine the order of Tests when tests have dependencies on each other Implement Graph Using Map - Java Find the maximum number present in a String Count number of subgraphs in a given graph Reverse a Stack using recursion - In Place (Without using extra memory) Check if given an edge is a bridge in the graph Convert Prefix to Postfix Expression Convert Roman Number to Integer Sort a given stack - Using Temporary Stack Convert Postfix to Prefix Expression Convert Integer to Roman String to Integer (AtoI - ASCII to Integer) - Recursive Solution Grouping of Anagrams Print Processes and its messages from a given log file Linear Search vs Binary Search K-Means Algorithm Count the number of nodes in a given binary tree Sieve of Eratosthenes - Find all Prime Numbers less than equal to N | Set 2 Longest contiguous character in a given String - O(N) Solution Convert Postfix to Infix Expression Collatz Conjecture - Steps to transform Number to 1 String to Integer (AtoI - ASCII to Integer) Find all Prime Numbers less than equal to N | Set 1 Longest substring with at most two unique characters Monotone Increasing Digits Convert Infix to Prefix Expression Find third largest element in a given array Find duplicates Characters in the given String Max Flow Problem - Ford-Fulkerson Algorithm 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16