Easy
- unique-email-addresses
- two-sum
- count-and-say
- symmetric-tree
- balanced-binary-tree
- valid-palindrome
- pascals-triangle
- pascals-triangle-ii
- buddy-strings
- third-maximum-number
- valid-mountain-array
- reverse-bits
- license-key-formatting
- find-pivot-index
- isomorphic-strings
- toeplitz-matrix
- word-pattern
- best-time-to-buy-and-sell-stock
Medium
- fruit-into-baskets
- number-of-islands
- clone-graph
- word-ladder
- course-schedule
- lru-cache
- permutations
- string-to-integer
- powx-n
- valid-sudoku
- divide-two-integers
- decode-ways
- max-increase-to-keep-city-skyline
- encode-and-decode-tiny-url
- max-area-of-island
- valid-parenthesis-string
- hand-of-straights
- validate-ip-address
- nth-digit
- find-and-replace-in-string
- set-matrix-zeroes
- sort-colors
- maximum-subarray
- next-permutation