Python-Leetcode-Algorithm 第一阶段：10个topic 100道easy题 HighestFrequency 2018/06/16 Array: 10 easy 1. Two Sum: https://leetcode.com/problems/two-sum/description/ 561. Array Partition I: https://leetcode.com/problems/array-partition-i/description/ 66. Plus One: https://leetcode.com/problems/plus-one/description/ 53. Maximum Subarray: https://leetcode.com/problems/maximum-subarray/description/ 122. Best Time to Buy and Sell Stock II: https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/description/ 169. Majority Element: https://leetcode.com/problems/majority-element/description/ 283. Move Zeroes: https://leetcode.com/problems/move-zeroes/description/ 121. Best Time to Buy and Sell Stock: https://leetcode.com/problems/best-time-to-buy-and-sell-stock/description/ 217. Contains Duplicate: https://leetcode.com/problems/contains-duplicate/description/ 88. Merge Sorted Array: https://leetcode.com/problems/merge-sorted-array/description/ String: 10 easy 13. Roman to Integer: https://leetcode.com/problems/roman-to-integer/description/ 344. Reverse String: https://leetcode.com/problems/reverse-string/description/ 14. Longest Common Prefix: https://leetcode.com/problems/longest-common-prefix/description/ 20. Valid Parentheses: https://leetcode.com/problems/valid-parentheses/description/ 38. Count and Say: https://leetcode.com/problems/count-and-say/description/ 67. Add Binary: https://leetcode.com/problems/add-binary/description/ 657. Judge Route Circle: https://leetcode.com/problems/judge-route-circle/description/ 28. Implement strStr(): https://leetcode.com/problems/implement-strstr/description/ 557. Reverse Words in a String III: https://leetcode.com/problems/reverse-words-in-a-string-iii/description/ 383. Ransom Note: https://leetcode.com/problems/ransom-note/description/ Math: 10 easy 9. Palindrome Number: https://leetcode.com/problems/palindrome-number/description/ 7. Reverse Integer: https://leetcode.com/problems/reverse-integer/description/ 258. Add Digits: https://leetcode.com/problems/add-digits/description/ 202. Happy Number: https://leetcode.com/problems/happy-number/description/ 172. Factorial Trailing Zeroes: https://leetcode.com/problems/factorial-trailing-zeroes/description/ 171. Excel Sheet Column Number: https://leetcode.com/problems/excel-sheet-column-number/description/ 326. Power of Three: https://leetcode.com/problems/power-of-three/description/ 268. Missing Number: https://leetcode.com/problems/missing-number/description/ 728. Self Dividing Numbers: https://leetcode.com/problems/self-dividing-numbers/description/ 69. Sqrt(x): https://leetcode.com/problems/sqrtx/discuss/25047/A-Binary-Search-Solution Bit Manipulation: 10 easy 136. Single Number: https://leetcode.com/problems/single-number/description/ 461. Hamming Distance: https://leetcode.com/problems/hamming-distance/description/ 371. Sum of Two Integers: https://leetcode.com/problems/sum-of-two-integers/description/ 169. Majority Element: https://leetcode.com/problems/majority-element/description/ 191. Number of 1 Bits: https://leetcode.com/problems/number-of-1-bits/description/ 268. Missing Number: https://leetcode.com/problems/missing-number/description/ 476. Number Complement: https://leetcode.com/problems/number-complement/description/ 231. Power of Two: https://leetcode.com/problems/power-of-two/description/ 190. Reverse Bits: https://leetcode.com/problems/reverse-bits/description/ 389. Find the Difference: https://leetcode.com/problems/find-the-difference/description/ Binary Search: 4 easy + 6 medium + 1 hard 167. Two Sum II - Input array is sorted: https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/description/ 35. Search Insert Position: https://leetcode.com/problems/search-insert-position/description/ 374. Guess Number Higher or Lower: https://leetcode.com/problems/guess-number-higher-or-lower/description/ 278. First Bad Version: https://leetcode.com/problems/first-bad-version/description/ 50. Pow(x, n): https://leetcode.com/problems/powx-n/description/ 153. Find Minimum in Rotated Sorted Array: https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/description/ 33. Search in Rotated Sorted Array: https://leetcode.com/problems/search-in-rotated-sorted-array/description/ 29. Divide Two Integers: https://leetcode.com/problems/divide-two-integers/description/ 287. Find the Duplicate Number: https://leetcode.com/problems/find-the-duplicate-number/description/ 240. Search a 2D Matrix II: https://leetcode.com/problems/search-a-2d-matrix-ii/description/ 4. Median of Two Sorted Arrays: https://leetcode.com/problems/median-of-two-sorted-arrays/description/ Sort: 3 easy + 5 medium + 2 hard 242. Valid Anagram: https://leetcode.com/problems/valid-anagram/description/ 349. Intersection of Two Arrays: https://leetcode.com/problems/intersection-of-two-arrays/description/ 350. Intersection of Two Arrays II: https://leetcode.com/problems/intersection-of-two-arrays-ii/description/ 148. Sort List: https://leetcode.com/problems/sort-list/description/ 56. Merge Intervals: https://leetcode.com/problems/merge-intervals/description/ 147. Insertion Sort List: https://leetcode.com/problems/insertion-sort-list/description/ 179. Largest Number: https://leetcode.com/problems/largest-number/description/ 280. Wiggle Sort: https://leetcode.com/problems/wiggle-sort/description/ 164. Maximum Gap: https://leetcode.com/problems/maximum-gap/description/ 296. Best Meeting Point: https://leetcode.com/problems/best-meeting-point/description/ Two Pointers: 9 easy + 1 medium 141. Linked List Cycle: https://leetcode.com/problems/linked-list-cycle/description/ 26. Remove Duplicates from Sorted Array: https://leetcode.com/problems/remove-duplicates-from-sorted-array/description/ 27. Remove Element: https://leetcode.com/problems/remove-element/description/ 234. Palindrome Linked List: https://leetcode.com/problems/palindrome-linked-list/description/ 28. 11. Container With Most Water: https://leetcode.com/problems/container-with-most-water/description/ 167. Two Sum II - Input array is sorted: https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/description/ 349. Intersection of Two Arrays: https://leetcode.com/problems/intersection-of-two-arrays/description/ 345. Reverse Vowels of a String: https://leetcode.com/problems/reverse-vowels-of-a-string/description/ 125. Valid Palindrome: https://leetcode.com/problems/valid-palindrome/description/ 350. Intersection of Two Arrays II: https://leetcode.com/problems/intersection-of-two-arrays-ii/description/ Dynamic Programming: 6 easy + 4 medium + 1 hard 53. Maximum Subarray: https://leetcode.com/problems/maximum-subarray/description/ 121. Best Time to Buy and Sell Stock: https://leetcode.com/problems/best-time-to-buy-and-sell-stock/description/ 70. Climbing Stairs: https://leetcode.com/problems/climbing-stairs/description/ 198. House Robber: https://leetcode.com/problems/house-robber/description/ 303. Range Sum Query - Immutable: https://leetcode.com/problems/range-sum-query-immutable/description/ 746. Min Cost Climbing Stairs: https://leetcode.com/problems/min-cost-climbing-stairs/description/ 5. Longest Palindromic Substring: https://leetcode.com/problems/longest-palindromic-substring/description/ 338. Counting Bits: https://leetcode.com/problems/counting-bits/description/ 152. Maximum Product Subarray: https://leetcode.com/problems/maximum-product-subarray/description/ 139. Word Break: https://leetcode.com/problems/word-break/description/ 10. Regular Expression Matching: https://leetcode.com/problems/regular-expression-matching/description/ Tree: 10 easy 104. Maximum Depth of Binary Tree: https://leetcode.com/problems/maximum-depth-of-binary-tree/description/ 226. Invert Binary Tree: https://leetcode.com/problems/invert-binary-tree/description/ 617. Merge Two Binary Trees: https://leetcode.com/problems/merge-two-binary-trees/description/ 100. Same Tree: https://leetcode.com/problems/same-tree/description/ 110. Balanced Binary Tree: https://leetcode.com/problems/balanced-binary-tree/description/ 235. Lowest Common Ancestor of a Binary Search Tree: https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree/description/ 108. Convert Sorted Array to Binary Search Tree: https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/description/ 669. Trim a Binary Search Tree: https://leetcode.com/problems/trim-a-binary-search-tree/description/ 101. Symmetric Tree: https://leetcode.com/problems/symmetric-tree/description/ 257. Binary Tree Paths: https://leetcode.com/problems/binary-tree-paths/description/ Hash Table: 10 easy 771. Jewels and Stones: https://leetcode.com/problems/jewels-and-stones/description/ 463. Island Perimeter: https://leetcode.com/problems/island-perimeter/description/ 219. Contains Duplicate II: https://leetcode.com/problems/contains-duplicate-ii/description/ 242. Valid Anagram: https://leetcode.com/problems/valid-anagram/description/ 760. Find Anagram Mappings: https://leetcode.com/problems/find-anagram-mappings/description/ 500. Keyboard Row: https://leetcode.com/problems/keyboard-row/description/ 387. First Unique Character in a String: https://leetcode.com/problems/first-unique-character-in-a-string/description/ 204. Count Primes: https://leetcode.com/problems/count-primes/description/ 205. Isomorphic Strings: https://leetcode.com/problems/isomorphic-strings/description/ 290. Word Pattern: https://leetcode.com/problems/word-pattern/description/