added leet code problems for hashtables: pa04

_pa/pa04.md

@@ -0,0 +1,17 @@
+---
+num: pa04
+ready: true
+desc: "Leetcode practice with hashtables and hashmaps"
+assigned: 2024-03-02 9:00:00.00-8
+---
+## Additional Practice Problems
+1. Two sum (easy):<https://leetcode.com/problems/two-sum/description/>
+2. Intersection of Two Arrays (easy) <https://leetcode.com/problems/intersection-of-two-arrays/description/>
+3. Contains Duplicate (easy) <https://leetcode.com/problems/contains-duplicate/description/>
+4. Ransom Note (easy) <https://leetcode.com/problems/ransom-note/description/>
+5. Happy Number (easy) <https://leetcode.com/problems/happy-number/description/>
+6. 4Sum II (medium) <https://leetcode.com/problems/4sum-ii/description>
+7. 3Sum (medium) <https://leetcode.com/problems/3sum/description/>
+8. 4Sum (medium) <https://leetcode.com/problems/4sum/description/>
+9. Longest Consecutive Sequence (medium) <https://leetcode.com/problems/longest-consecutive-sequence/description/>
+