| Id | Exercise | Solution | |
|---|---|---|---|
| #0001 | Two Sum | Hashmap | |
| #0009 | Palindrome number | No string/array conversion | |
| #0020 | Valid parentheses | Stack solution | |
| #0058 | Length of Last Word | Agnostic solution | Ruby built-in functions |
| #0169 | Majority element | tally and max | |
| #0217 | Contains duplicate | Ruby built-in function | |
| #1768 | Merge Strings Alternately | Ruby | |
| #2404 | Most Frequent Even Element | Hash | |
| #3178 | Find the Child Who Has the Ball After K Seconds | Ruby |