When you count to 20, you start at 1 (or zero) and count on until you reach 20. Each number is one more than the last. When you count back from 20, you start at 20 and count back until you reach 1 (or ...

Bernie is counting flowers which have grown in three window boxes. There are 10 in the first box, 9 in the second and 8 in the third. Bernie adds the three numbers together by counting on in units.

Many developers share their LeetCode solutions on GitHub. Look for repositories that are well-organized by topic or problem number, have clear explanations, and show good code quality. Some popular ...