Problems # Status Problem Level Completes Likes 176 Sum of all Unique elements in a given array Beginner % 0 177 Java program to find the largest element in array Beginner % 0 178 Convert Infix to Postfix Expression Medium % 0 179 Find three smallest elements in a given array Beginner % 0 180 Evaluation of Infix expressions Medium % 0 181 Stack Java Class - Explained Beginner % 0 182 Convert Prefix to Infix Expression Medium % 0 183 Least Recently Used (LRU) Cache – Using LinkedHashSet and Deque | Set 2 Hard % 0 184 Merge K sorted Linked List - Using Priority Queue Hard % 0 185 Infix, Postfix and Prefix Notations/Expressions Beginner % 0 186 Count Set bits in a given Number Beginner % 0 187 Check if array contains all unique or distinct numbers. Beginner % 0 188 Product of all Unique elements in a given array. Beginner % 0 189 Valid Multiple Parentheses Medium % 0 190 Reverse a given number – Java Code Beginner % 0 191 Check if given number is perfect square - O(√N) Solution Beginner % 0 192 Least Recently Used (LRU) Cache – Using HashMap and Doubly Linked List | Set 1 Hard % 0 193 Find first three largest elements in a given array Beginner % 0 194 Selection Sort – Java Implementation Beginner % 0 195 Print Number with its Sign in Java Beginner % 0 196 Find the nearest building which has bike | Find nearest specific vertex from source in a graph. Hard % 0 197 Valid Brackets – Part 2 | Stack Method Beginner % 0 198 Find the roots of Quadratic Equation – Java Program Beginner % 0 199 Given two strings validate the output string Beginner % 0 200 Generate all the strings of length n from 0 to k-1. Medium % 0 201 Find two smallest elements in a given array Beginner % 0 202 Front and Back Search in an Array Beginner % 0 203 Print all Unique elements in a given array Beginner % 0 204 Multiply with power of 2 without using pow() or * operator Beginner % 0 205 Find Number of reverse pairs in an array Medium % 0 206 Find first two largest elements in a given array Beginner % 0 207 Calculate Logn base r – Java Implementation Beginner % 0 208 Max Flow Problem – Introduction Hard % 0 209 Dijkstra Algorithm Implementation – TreeSet and Pair Class Hard % 0 210 Java Program to find Sum the elements of an Array Beginner % 0 Sum of all Unique elements in a given array Java program to find the largest element in array Convert Infix to Postfix Expression Find three smallest elements in a given array Evaluation of Infix expressions Stack Java Class - Explained Convert Prefix to Infix Expression Least Recently Used (LRU) Cache – Using LinkedHashSet and Deque | Set 2 Merge K sorted Linked List - Using Priority Queue Infix, Postfix and Prefix Notations/Expressions Count Set bits in a given Number Check if array contains all unique or distinct numbers. Product of all Unique elements in a given array. Valid Multiple Parentheses Reverse a given number – Java Code Check if given number is perfect square - O(√N) Solution Least Recently Used (LRU) Cache – Using HashMap and Doubly Linked List | Set 1 Find first three largest elements in a given array Selection Sort – Java Implementation Print Number with its Sign in Java Find the nearest building which has bike | Find nearest specific vertex from source in a graph. Valid Brackets – Part 2 | Stack Method Find the roots of Quadratic Equation – Java Program Given two strings validate the output string Generate all the strings of length n from 0 to k-1. Find two smallest elements in a given array Front and Back Search in an Array Print all Unique elements in a given array Multiply with power of 2 without using pow() or * operator Find Number of reverse pairs in an array Find first two largest elements in a given array Calculate Logn base r – Java Implementation Max Flow Problem – Introduction Dijkstra Algorithm Implementation – TreeSet and Pair Class Java Program to find Sum the elements of an Array 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16