[Easy]
Floyd's cycle finding algorithm: https://leetcode.com/problems/linked-list-cycle/
Split string into balanced substrings: https://leetcode.com/problems/split-a-string-in-balanced-strings/
Range sum of bst: https://leetcode.com/problems/range-sum-of-bst/
Remove outermost parentheses: https://leetcode.com/problems/remove-outermost-parentheses/
Factorial trailing zeros: https://leetcode.com/problems/factorial-trailing-zeroes/
Count primes: https://leetcode.com/problems/count-primes/
[Medium]
Minimum number of operations to move all balls to each box: https://leetcode.com/problems/minimum-number-of-operations-to-move-all-balls-to-each-box/
Max increase to keep city skyline: https://leetcode.com/problems/max-increase-to-keep-city-skyline/
Group the people given the group size they belong to: https://leetcode.com/problems/group-the-people-given-the-group-size-they-belong-to/
Sort matrix diagonally: https://leetcode.com/problems/sort-the-matrix-diagonally/ (**)
Find corresponding node in a cloned tree: https://leetcode.com/problems/find-a-corresponding-node-of-a-binary-tree-in-a-clone-of-that-tree/
Min operations to make array equal: https://leetcode.com/problems/minimum-operations-to-make-array-equal/ (**)
Sum of nodes with even valued grandparents: https://leetcode.com/problems/sum-of-nodes-with-even-valued-grandparent/
Deepest leaves sum: https://leetcode.com/problems/deepest-leaves-sum/
Count vowel strings: https://leetcode.com/problems/count-sorted-vowel-strings/ (**)
Remove leaf nodes with target value: https://leetcode.com/problems/delete-leaves-with-a-given-value/ (**)
Smallest set of vertices: https://leetcode.com/problems/minimum-number-of-vertices-to-reach-all-nodes/ (**)
Merged linked lists: https://leetcode.com/problems/merge-in-between-linked-lists/
Count good nodes in binary tree: https://leetcode.com/problems/count-good-nodes-in-binary-tree/
Find bottom left leaf value: https://leetcode.com/problems/find-bottom-left-tree-value/
Find duplicates in array: https://leetcode.com/problems/find-all-duplicates-in-an-array/ (**) GFG
Find replace pattern: https://leetcode.com/problems/find-and-replace-pattern/ (**)
Flip equivalent binary trees: https://leetcode.com/problems/flip-equivalent-binary-trees/ (**)
kth smallest in BST: https://leetcode.com/problems/kth-smallest-element-in-a-bst/ (**) GFG
Largest value in tree row: https://leetcode.com/problems/find-largest-value-in-each-tree-row/
LCA of deepest leaves: https://leetcode.com/problems/lowest-common-ancestor-of-deepest-leaves/ (**)
Max diff between node and ancestor: https://leetcode.com/problems/maximum-difference-between-node-and-ancestor/ (**)
Min fibonacci numbers to sum to k: https://leetcode.com/problems/find-the-minimum-number-of-fibonacci-numbers-whose-sum-is-k/ (Can improve)
Min add to make valid parantheses: https://leetcode.com/problems/minimum-add-to-make-parentheses-valid/
Queens that can attack king: https://leetcode.com/problems/queens-that-can-attack-the-king/
Score of parentheses: https://leetcode.com/problems/score-of-parentheses/ (**)
Sort characters by frequency: https://leetcode.com/problems/sort-characters-by-frequency/
Top k frequent elements: https://leetcode.com/problems/top-k-frequent-elements/ (Can improve)
Validate stack sequences: https://leetcode.com/problems/validate-stack-sequences/
Convert to base -2: https://leetcode.com/problems/convert-to-base-2/ (**) GFG
Rearrange words in a sentence: https://leetcode.com/problems/rearrange-words-in-a-sentence/ (Can improve)
Min cost to delete repeating letters: https://leetcode.com/problems/minimum-deletion-cost-to-avoid-repeating-letters/ (**) Stack based
Odd even linked list: https://leetcode.com/problems/odd-even-linked-list/ (Can improve)
Binary tree inorder traversal: https://leetcode.com/problems/binary-tree-inorder-traversal/
Binary tree level order traversal: https://leetcode.com/problems/binary-tree-level-order-traversal/
Generate all subsets: https://leetcode.com/problems/subsets/ (**) (Can improve)