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Sentence Similarity III Medium Trapping Rain Water Hard Contains Duplicate II Easy Best Time to Buy And Sell Stock Easy Minimum Recolors to Get K Consecutive Black Blocks Easy Minimum Difference Between Highest And Lowest of K Scores Easy Number of Sub Arrays of Size K and Avg Greater than or Equal to Threshold Medium Grumpy Bookstore Owner Medium Alternating Groups II Medium Longest Substring Without Repeating Characters Medium Longest Repeating Character Replacement Medium Permutation In String Medium Frequency of The Most Frequent Element Medium Fruit into Basket Medium Maximum Number of Vowels in a Substring of Given Length Medium Minimum Number of Flips to Make The Binary String Alternating Medium Defuse the Bomb Easy Minimum Size Subarray Sum Medium Find K Closest Elements Medium Minimum Operations to Reduce X to Zero Medium Get Equal Substrings Within Budget Medium Number of Substrings Containing All Three Characters Medium Binary Subarrays with Sum Medium Count Number of Nice 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Spells and Potions Medium Search a 2D Matrix Medium Koko Eating Bananas Medium Capacity to Ship Packages Within D Days Medium Maximum Candies Allocated to K Children Medium House Robber IV Medium Minimize the Maximum Difference of Pairs Medium Minimized Maximum of Products Distributed to Any Store Medium Minimum Limit of Balls in a Bag Medium Minimum Time to Repair Cars Medium Find Minimum In Rotated Sorted Array Medium Search In Rotated Sorted Array Medium Search In Rotated Sorted Array II Medium Time Based Key Value Store Medium Find First And Last Position of Element In Sorted Array Medium Maximum Number of Removable Characters Medium Most Beautiful Item for Each Query Medium Search Suggestions System Medium Count the Number of Fair Pairs Medium Split Array Largest Sum Hard Find K-th Smallest Pair Distance Hard Median of Two Sorted Arrays Hard Find in Mountain Array Hard Reverse Linked List Easy Merge Two Sorted Lists Easy Linked List Cycle Easy Palindrome Linked List Easy Remove Linked List Elements Easy Remove Duplicates From Sorted List Easy Middle of the Linked List Easy Intersection of Two Linked Lists Easy Merge in Between Linked Lists Medium Merge Nodes in Between Zeros Medium Find the Minimum and Maximum Number of Nodes Between Critical Points Medium Remove Nodes From Linked List Medium Reorder List Medium Maximum Twin Sum Of A Linked List Medium Remove Nth Node From End of List Medium Delete Nodes From Linked List Present in Array Medium Swapping Nodes in a Linked List Medium Copy List With Random Pointer Medium Design Linked List Medium Design Browser History Medium Add Two Numbers Medium Find The Duplicate Number Medium Swap Nodes In Pairs Medium Sort List Medium Partition List Medium Rotate List Medium Reverse Linked List II Medium Design Circular Queue Medium Insertion Sort List Medium Split Linked List in Parts Medium LRU Cache Medium LFU Cache Hard Merge K Sorted Lists Hard Reverse Nodes In K Group Hard Binary Tree Inorder Traversal Easy Binary Tree Preorder Traversal Easy Binary Tree Postorder Traversal Easy N-ary Tree Postorder Traversal Easy Invert Binary Tree Easy Maximum Depth of Binary Tree Easy Diameter of Binary Tree Easy Balanced Binary Tree Easy Same Tree Easy Subtree of Another Tree Easy Convert Sorted Array to Binary Search Tree Easy Merge Two Binary Trees Easy Path Sum Easy Range Sum of BST Easy Leaf-Similar Trees Easy Evaluate Boolean Binary Tree Easy Binary Tree Vertical Order Traversal Medium Create Binary Tree From Descriptions Medium Populating Next Right Pointers In Each Node Medium Construct String From Binary Tree Medium Lowest Common Ancestor of a Binary Search Tree Medium Insert into a Binary Search Tree Medium Delete Node in a BST Medium Binary Tree Level Order Traversal Medium Binary Tree Right Side View Medium Reverse Odd Levels of Binary Tree Medium Minimum Number of Operations to Sort a Binary Tree by Level Medium Kth Largest Sum in a Binary Tree Medium Cousins in Binary Tree II Medium Minimum Distance between BST Nodes Easy Symmetric Tree Easy Linked List in Binary Tree Medium Minimum Time to Collect All Apples in a Tree Medium Binary Tree Zigzag Level Order Traversal Medium Construct Quad Tree Medium Find Duplicate Subtrees Medium Check Completeness of a Binary Tree Medium Construct Binary Tree from Inorder and Postorder Traversal Medium Maximum Width of Binary Tree Medium Time Needed to Inform All Employees Medium Count Good Nodes In Binary Tree Medium Validate Binary Search Tree Medium Kth Smallest Element In a Bst Medium Construct Binary Tree From Preorder And Inorder Traversal Medium Construct Binary Tree from Preorder and Postorder Traversal Medium Unique Binary Search Trees Medium Unique Binary Search Trees II Medium Number of Good Leaf Nodes Pairs Medium Sum Root to Leaf Numbers Medium House Robber III Medium Flip Equivalent Binary Trees Medium Operations On Tree Medium All Possible Full Binary Trees Medium Find Bottom Left Tree Value Medium Trim a Binary Search Tree Medium Binary Search Tree Iterator Medium Validate Binary Tree Nodes Medium Find Largest Value in Tree Row Medium Pseudo-Palindromic Paths in a Binary Tree Medium

2563. Count the Number of Fair Pairs - Explanation

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