Modify README.md

Author: hypeagle

README.md

@@ -26,5 +26,83 @@
 [38. Count and Say](https://leetcode.com/problems/count-and-say) [[C](./src/38.c)]
 
 ## Medium
+[2. Add Two Numbers](https://leetcode.com/problems/add-two-numbers) [[C](./src/2.c)]
 
-## Hard
+[3. Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters) [[C](./src/3.c)]
+
+[5. Longest Palindromic Substring](https://leetcode.com/problems/longest-palindromic-substring) [[C](./src/5.c)]
+
+[6. ZigZag Conversion](https://leetcode.com/problems/zigzag-conversion) [[C](./src/6.c)]
+
+[8. String to Integer (atoi)](https://leetcode.com/problems/string-to-integer-atoi) [[C](./src/8.c)]
+
+[11. Container With Most Water](https://leetcode.com/problems/container-with-most-water) [[C](./src/11.c)]
+
+[12. Integer to Roman](https://leetcode.com/problems/integer-to-roman) [[C](./src/12.c)]
+
+[15. 3Sum](https://leetcode.com/problems/3sum) [[C](./src/15.c)]
+
+[16. 3Sum Closest](https://leetcode.com/problems/3sum-closest) [[C](./src/16.c)]
+
+[17. Letter Combinations of a Phone Number](https://leetcode.com/problems/letter-combinations-of-a-phone-number) [[C](./src/17.c)]
+
+[18. 4Sum](https://leetcode.com/problems/4sum) [[C](./src/18.c)]
+
+[19. Remove Nth Node From End of List](https://leetcode.com/problems/remove-nth-node-from-end-of-list) [[C](./src/19.c)]
+
+[22. Generate Parentheses](https://leetcode.com/problems/generate-parentheses) [[C](./src/22.c)]
+
+[24. Swap Nodes in Pairs](https://leetcode.com/problems/swap-nodes-in-pairs) [[C](./src/24.c)]
+
+[29. Divide Two Integers](https://leetcode.com/problems/divide-two-integers) [[C](./src/29.c)]
+
+[31. Next Permutation](https://leetcode.com/problems/next-permutation) [[C](./src/31.c)]
+
+[33. Search in Rotated Sorted Array](https://leetcode.com/problems/search-in-rotated-sorted-array) [[C](./src/33.c)]
+
+[34. Search for a Range](https://leetcode.com/problems/search-for-a-range) [[C](./src/34.c)]
+
+[36. Valid Sudoku](https://leetcode.com/problems/valid-sudoku) [[C](./src/36.c)]
+
+[39. Combination Sum](https://leetcode.com/problems/combination-sum) [[C](./src/39.c)]
+
+[40. Combination Sum II](https://leetcode.com/problems/combination-sum-ii) [[C](./src/40.c)]
+
+[43. Multiply Strings](https://leetcode.com/problems/multiply-strings) [[C](./src/43.c)]
+
+[46. Permutations](https://leetcode.com/problems/permutations) [[C](./src/46.c)]
+
+[47. Permutations II](https://leetcode.com/problems/permutations-ii) [[C](./src/47.c)]
+
+[48. Rotate Image](https://leetcode.com/problems/rotate-image) [[C](./src/48.c)]
+
+[49. Group Anagrams](https://leetcode.com/problems/group-anagrams) [[C](./src/49.c)]
+
+[50. Pow(x, n)](https://leetcode.com/problems/powx-n) [[C](./src/50.c)]
+
+## Hard
+[4. Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays) [[C](./src/4.c)]
+
+[10. Regular Expression Matching](https://leetcode.com/problems/regular-expression-matching) [[C](./src/10.c)]
+
+[23. Merge k Sorted Lists](https://leetcode.com/problems/merge-k-sorted-lists) [[C](./src/23.c)]
+
+[25. Reverse Nodes in k-Group](https://leetcode.com/problems/reverse-nodes-in-k-group) [[C](./src/25.c)]
+
+[30. Substring with Concatenation of All Words](https://leetcode.com/problems/substring-with-concatenation-of-all-words) [[C](./src/30.c)]
+
+[32. Longest Valid Parentheses](https://leetcode.com/problems/longest-valid-parentheses) [[C](./src/32.c)]
+
+[37. Sudoku Solver](https://leetcode.com/problems/sudoku-solver) [[C](./src/37.c)]
+
+[41. First Missing Positive](https://leetcode.com/problems/first-missing-positive) [[C](./src/41.c)]
+
+[42. Trapping Rain Water](https://leetcode.com/problems/trapping-rain-water) [[C](./src/42.c)]
+
+[44. Wildcard Matching](https://leetcode.com/problems/wildcard-matching) [[C](./src/44.c)]
+
+[45. Jump Game II](https://leetcode.com/problems/jump-game-ii) [[C](./src/45.c)]
+
+[51. N-Queens](https://leetcode.com/problems/n-queens) [[Swift](./swift/51.swift)]
+
+[52. N-Queens II](https://leetcode.com/problems/n-queens-ii) [[Swift](./swift/52.swift)]