ID	Title	Difficulty
60	Permutation Sequence	Medium
61	Rotate List	Medium
62	Unique Paths	Medium
63	Unique Paths II	Medium
64	Minimum Path Sum	Medium
65	Valid Number	Hard
66	Plus One	Easy
67	Add Binary	Easy
68	Text Justification	Hard
69	Sqrt(x)	Easy
70	Climbing Stairs	Easy
71	Simplify Path	Medium
72	Edit Distance	Hard
73	Set Matrix Zeroes	Medium
74	Search a 2D Matrix	Medium
75	Sort Colors	Medium
76	Minimum Window Substring	Hard
77	Combinations	Medium
78	Subsets	Medium
79	Word Search	Medium
80	Remove Duplicates from Sorted Array II	Medium
81	Search in Rotated Sorted Array II	Medium
82	Remove Duplicates from Sorted List II	Medium
83	Remove Duplicates from Sorted List	Easy
84	Largest Rectangle in Histogram	Hard
85	Maximal Rectangle	Hard
86	Partition List	Medium
87	Scramble String	Hard
88	Merge Sorted Array	Easy
89	Gray Code	Medium