整理一下
| ID | Title | Difficulty | Java | Python | C++ | SQL |
|---|---|---|---|---|---|---|
| 1 | Two Sum | Easy | YES | YES | ||
| 2 | Add Two Numbers | Medium | YES | YES | ||
| 3 | Longest Substring Without Repeating Characters | Medium | YES | YES | ||
| 4 | Median of Two Sorted Arrays | Hard | ||||
| 5 | Longest Palindromic Substring | Medium | ||||
| 6 | ZigZag Conversion | Medium | ||||
| 7 | Reverse Integer | Easy | ||||
| 8 | String to Integer (atoi) | Medium | ||||
| 9 | Palindrome Number | Easy | ||||
| 10 | Regular Expression Matching | Hard | ||||
| 176 | Second Highest Salary | Easy | YES |