| 121 | Best Time to Buy and Sell Stock | Easy |
| 122 | Best Time to Buy and Sell Stock II | Easy |
| 125 | Valid Palindrome | Easy |
| 136 | Single Number | Easy |
| 141 | Linked List Cycle | Easy |
| 155 | Min Stack | Easy |
| 160 | Intersection of Two Linked Lists | Easy |
| 167 | Two Sum II - Input array is sorted | Easy |
| 168 | Excel Sheet Column Title | Easy |
| 169 | Majority Element | Easy |
| 171 | Excel Sheet Column Number | Easy |
| 172 | Factorial Trailing Zeroes | Easy |
| 175 | Combine Two Tables | Easy |
| 176 | Second Highest Salary | Easy |
| 181 | Employees Earning More Than Their Managers | Easy |
| 182 | Duplicate Emails | Easy |
| 183 | Customers Who Never Order | Easy |
| 191 | Number of 1 Bits | Easy |
| 196 | Delete Duplicate Emails | Easy |
| 198 | House Robber | Easy |
| 202 | Happy Number | Easy |
| 205 | Isomorphic Strings | Easy |
| 206 | Reverse Linked List | Easy |
| 219 | Contains Duplicate II | Easy |
| 226 | Invert Binary Tree | Easy |
| 228 | Summary Ranges | Easy |
| 231 | Power of Two | Easy |
| 232 | Implement Queue using Stacks | Easy |
| 234 | Palindrome Linked List | Easy |
| 242 | Valid Anagram | Easy |