| 492 | Construct the Rectangle | Math | Easy |
| 495 | Teemo Attacking | ArraySimulation | Easy |
| 496 | Next Greater Element I | ArrayHash TableStack+1 | Easy |
| 500 | Keyboard Row | ArrayHash TableString | Easy |
| 501 | Find Mode in Binary Search Tree | TreeDepth-First SearchBinary Search Tree+1 | Easy |
| 504 | Base 7 | MathString | Easy |
| 506 | Relative Ranks | ArraySortingHeap (Priority Queue) | Easy |
| 507 | Perfect Number | Math | Easy |
| 509 | Fibonacci Number | MathDynamic ProgrammingRecursion+1 | Easy |
| 511 | Game Play Analysis I | Database | Easy |
| 520 | Detect Capital | String | Easy |
| 521 | Longest Uncommon Subsequence I | String | Easy |
| 530 | Minimum Absolute Difference in BST | TreeDepth-First SearchBreadth-First Search+2 | Easy |
| 541 | Reverse String II | Two PointersString | Easy |
| 543 | Diameter of Binary Tree | TreeDepth-First SearchBinary Tree | Easy |
| 551 | Student Attendance Record I | String | Easy |
| 557 | Reverse Words in a String III | Two PointersString | Easy |
| 559 | Maximum Depth of N-ary Tree | TreeDepth-First SearchBreadth-First Search | Easy |
| 561 | Array Partition | ArrayGreedySorting+1 | Easy |
| 563 | Binary Tree Tilt | TreeDepth-First SearchBinary Tree | Easy |
| 566 | Reshape the Matrix | ArrayMatrixSimulation | Easy |
| 572 | Subtree of Another Tree | TreeDepth-First SearchString Matching+2 | Easy |
| 575 | Distribute Candies | ArrayHash Table | Easy |
| 577 | Employee Bonus | Database | Easy |
| 584 | Find Customer Referee | Database | Easy |
| 586 | Customer Placing the Largest Number of Orders | Database | Easy |
| 589 | N-ary Tree Preorder Traversal | StackTreeDepth-First Search | Easy |
| 590 | N-ary Tree Postorder Traversal | StackTreeDepth-First Search | Easy |
| 594 | Longest Harmonious Subsequence | ArrayHash TableSliding Window+2 | Easy |
| 595 | Big Countries | Database | Easy |
| 596 | Classes With at Least 5 Students | Database | Easy |
| 598 | Range Addition II | ArrayMath | Easy |
| 599 | Minimum Index Sum of Two Lists | ArrayHash TableString | Easy |
| 605 | Can Place Flowers | ArrayGreedy | Easy |
| 607 | Sales Person | Database | Easy |
| 610 | Triangle Judgement | Database | Easy |
| 617 | Merge Two Binary Trees | TreeDepth-First SearchBreadth-First Search+1 | Easy |
| 619 | Biggest Single Number | Database | Easy |
| 620 | Not Boring Movies | Database | Easy |
| 627 | Swap Salary | Database | Easy |
| 628 | Maximum Product of Three Numbers | ArrayMathSorting | Easy |
| 637 | Average of Levels in Binary Tree | TreeDepth-First SearchBreadth-First Search+1 | Easy |
| 643 | Maximum Average Subarray I | ArraySliding Window | Easy |
| 645 | Set Mismatch | ArrayHash TableBit Manipulation+1 | Easy |
| 653 | Two Sum IV - Input is a BST | Hash TableTwo PointersTree+4 | Easy |
| 657 | Robot Return to Origin | StringSimulation | Easy |
| 661 | Image Smoother | ArrayMatrix | Easy |
| 671 | Second Minimum Node In a Binary Tree | TreeDepth-First SearchBinary Tree | Easy |
| 674 | Longest Continuous Increasing Subsequence | Array | Easy |
| 680 | Valid Palindrome II | Two PointersStringGreedy | Easy |