# Status Problem Level Completes Likes 106 Convert Prefix to Infix Expression Medium % 0 107 Least Recently Used (LRU) Cache – Using LinkedHashSet and Deque | Set 2 Hard % 0 108 Merge K sorted Linked List - Using Priority Queue Hard % 0 109 Count Set bits in a given Number Beginner % 1 110 Valid Multiple Parentheses Medium % 1 111 Check if given number is perfect square - O(√N) Solution Beginner % 0 112 Find first three largest elements in a given array Beginner % 0 113 Find the nearest building which has bike | Find nearest specific vertex from source in a graph. Hard % 0 114 Valid Brackets – Part 2 | Stack Method Beginner % 0 115 Given two strings validate the output string Beginner % 0 116 Generate all the strings of length n from 0 to k-1. Medium % 0 117 Find two smallest elements in a given array Beginner % 0 118 Find Number of reverse pairs in an array Hard % 1 119 Max Flow Problem – Introduction Hard % 0 120 Dijkstra Algorithm Implementation – TreeSet and Pair Class Hard % 0 121 Heap Sort – Java Implementation Medium % 0 122 Find no of reverse pairs in an array which is sorted in two parts in O(N) Medium % 1 123 Dijkstra’s – Shortest Path Algorithm (SPT) – Adjacency List and Priority Queue – Java Implementation Hard % 0 124 Check if given number is Prime - O(√N) Solution – Java Program Medium % 0 125 Print First N Prime Numbers - Java Code Beginner % 0 126 Dijkstra’s – Shortest Path Algorithm (SPT) – Adjacency List and Min Heap – Java Implementation Hard % 0 127 Swap two numbers using Bitwise XOR Operator Medium % 1 128 Dijkstra’s – Shortest Path Algorithm (SPT) - Adjacency Matrix - Java Implementation Hard % 0 129 Fizz Buzz Challenge - Java Implementation Beginner % 0 130 Dijkstra's – Shortest Path Algorithm (SPT) Hard % 0 131 Prim’s – Minimum Spanning Tree (MST) |using Adjacency List and Priority Queue without decrease key in O(ElogV) Hard % 0 132 Graph – Find Cycle in Undirected Graph using Disjoint Set (Union-Find) Hard % 0 133 Graph – Count all paths between source and destination Medium % 1 134 Graph – Detect Cycle in a Directed Graph using colors Hard % 0 135 Graph – Detect Cycle in an Undirected Graph using DFS Medium % 0 136 Snake and Ladder Problem Hard % 1 137 Graph – Depth First Search in Disconnected Graph Medium % 1 138 Graph – Depth First Search using Recursion Beginner % 1 139 Minimum Copy Paste Operations Medium % 0 140 Count and print all Subarrays with product less than K in O(n) Hard % 0 Convert Prefix to Infix Expression Least Recently Used (LRU) Cache – Using LinkedHashSet and Deque | Set 2 Merge K sorted Linked List - Using Priority Queue Count Set bits in a given Number Valid Multiple Parentheses Check if given number is perfect square - O(√N) Solution Find first three largest elements in a given array Find the nearest building which has bike | Find nearest specific vertex from source in a graph. Valid Brackets – Part 2 | Stack Method 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 Find Number of reverse pairs in an array Max Flow Problem – Introduction Dijkstra Algorithm Implementation – TreeSet and Pair Class Heap Sort – Java Implementation Find no of reverse pairs in an array which is sorted in two parts in O(N) Dijkstra’s – Shortest Path Algorithm (SPT) – Adjacency List and Priority Queue – Java Implementation Check if given number is Prime - O(√N) Solution – Java Program Print First N Prime Numbers - Java Code Dijkstra’s – Shortest Path Algorithm (SPT) – Adjacency List and Min Heap – Java Implementation Swap two numbers using Bitwise XOR Operator Dijkstra’s – Shortest Path Algorithm (SPT) - Adjacency Matrix - Java Implementation Fizz Buzz Challenge - Java Implementation Dijkstra's – Shortest Path Algorithm (SPT) Prim’s – Minimum Spanning Tree (MST) |using Adjacency List and Priority Queue without decrease key in O(ElogV) Graph – Find Cycle in Undirected Graph using Disjoint Set (Union-Find) Graph – Count all paths between source and destination Graph – Detect Cycle in a Directed Graph using colors Graph – Detect Cycle in an Undirected Graph using DFS Snake and Ladder Problem Graph – Depth First Search in Disconnected Graph Graph – Depth First Search using Recursion Minimum Copy Paste Operations Count and print all Subarrays with product less than K in O(n) 1 2 3 4 5 6 7 8 9