Easy Foundations 50

50 essential Easy problems for building solid algorithmic foundations.

50 道題目

#	題目	難度	Rating
1	1. Two Sum	Easy	1116
2	9. Palindrome Number	Easy	1168
3	13. Roman to Integer	Easy	1258
4	14. Longest Common Prefix	Easy	1170
5	20. Valid Parentheses	Easy	1211
6	21. Merge Two Sorted Lists	Easy	1168
7	26. Remove Duplicates from Sorted Array	Easy	1169
8	27. Remove Element	Easy	1153
9	35. Search Insert Position	Easy	1164
10	53. Maximum Subarray	Medium	1409
11	58. Length of Last Word	Easy	1156
12	66. Plus One	Easy	1151
13	67. Add Binary	Easy	1160
14	69. Sqrt(x)	Easy	1178
15	70. Climbing Stairs	Easy	1232
16	83. Remove Duplicates from Sorted List	Easy	1169
17	88. Merge Sorted Array	Easy	1165
18	94. Binary Tree Inorder Traversal	Easy	1250
19	100. Same Tree	Easy	1176
20	101. Symmetric Tree	Easy	1200
21	104. Maximum Depth of Binary Tree	Easy	1116
22	107. Binary Tree Level Order Traversal II	Medium	1436
23	108. Convert Sorted Array to Binary Search Tree	Easy	1281
24	110. Balanced Binary Tree	Easy	1194
25	111. Minimum Depth of Binary Tree	Easy	1248
26	112. Path Sum	Easy	1181
27	118. Pascal's Triangle	Easy	1168
28	119. Pascal's Triangle II	Easy	1178
29	121. Best Time to Buy and Sell Stock	Easy	1487
30	122. Best Time to Buy and Sell Stock II	Medium	1486
31	125. Valid Palindrome	Easy	1138
32	136. Single Number	Easy	1150
33	141. Linked List Cycle	Easy	1302
34	144. Binary Tree Preorder Traversal	Easy	1258
35	145. Binary Tree Postorder Traversal	Easy	1214
36	169. Majority Element	Easy	1235
37	190. Reverse Bits	Easy	1149
38	191. Number of 1 Bits	Easy	1088
39	202. Happy Number	Easy	1188
40	203. Remove Linked List Elements	Easy	1222
41	206. Reverse Linked List	Easy	1186
42	217. Contains Duplicate	Easy	1160
43	226. Invert Binary Tree	Easy	1160
44	231. Power of Two	Easy	1154
45	234. Palindrome Linked List	Easy	1281
46	242. Valid Anagram	Easy	1151
47	268. Missing Number	Easy	1114
48	278. First Bad Version	Easy	1161
49	338. Counting Bits	Easy	1203
50	543. Diameter of Binary Tree	Easy	1287