Front-End coding problems including algorithms and JavaScript ones.

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1. implement curry()JavaScript1206 accepted
3. implement Array.prototype.flat()JavaScript1161 accepted
4. implement basic throttle()JavaScript Lodash689 accepted
19. find corresponding node in two identical DOM tree JavaScript583 accepted
6. implement basic debounce()JavaScript Lodash576 accepted
16. create an Event Emitter JavaScript496 accepted
58. get DOM tree height JavaScript Algorithm DOM429 accepted
9. decode message JavaScript419 accepted
10. first bad version JavaScript Algorithm401 accepted
11. what is Composition? create a pipe()JavaScript391 accepted
2. implement curry() with placeholder support JavaScript388 accepted
8. can you shuffle() an array?JavaScript381 accepted
18. Improve a function JavaScript375 accepted
17. Create a simple store for DOM element JavaScript375 accepted
32. implement `Promise.all()`JavaScript359 accepted
14. Implement a general memoization function - `memo()`JavaScript336 accepted
23. create a sum()JavaScript313 accepted
104. Traverse DOM level by level JavaScript Algorithm DOM310 accepted
25. Reorder array with new indexes JavaScript Algorithm294 accepted
28. implement clearAllTimeout()JavaScript281 accepted
7. implement debounce() with leading & trailing option JavaScript Lodash251 accepted
15. implement a simple DOM wrapper to support method chaining like jQuery JavaScript250 accepted
151. implement Array.prototype.map()JavaScript228 accepted
29. implement async helper - `sequence()`JavaScript228 accepted
68. get DOM tags JavaScript Algorithm DOM227 accepted
113. Virtual DOM I JavaScript Algorithm DOM226 accepted
39. implement range()JavaScript224 accepted
5. implement throttle() with leading & trailing option JavaScript Lodash215 accepted
64. auto-retry Promise on rejection JavaScript209 accepted
20. Detect data type in JavaScript JavaScript199 accepted
57. create an Observable JavaScript195 accepted
35. implement `Promise.race()`JavaScript194 accepted
33. implement `Promise.allSettled()`JavaScript193 accepted
131. implement _.chunk()JavaScript Lodash189 accepted
13. Implement a Queue by using Stack JavaScript Algorithm ByteDance187 accepted
148. create a counter object JavaScript183 accepted
89. Next Right Sibling JavaScript DOM Microsoft181 accepted
34. implement `Promise.any()`JavaScript175 accepted
110. serialize and deserialize binary tree JavaScript Algorithm168 accepted
26. implement Object.assign()JavaScript168 accepted
92. throttle Promises JavaScript166 accepted
46. implement `_.once()`JavaScript Lodash162 accepted
138. Intersection of two sorted arrays JavaScript Algorithm160 accepted
91. invert a binary tree JavaScript Algorithm160 accepted
30. implement async helper - `parallel()`JavaScript151 accepted
121. A number sequence JavaScript149 accepted
63. create `_.cloneDeep()`JavaScript Algorithm Lodash142 accepted
24. create a Priority Queue in JavaScript JavaScript Algorithm142 accepted
107. Find the largest difference JavaScript Algorithm140 accepted
123. implement Promise.prototype.finally()JavaScript139 accepted
105. find the first duplicate character in a string JavaScript Apple138 accepted
67. create your own Promise JavaScript Airbnb138 accepted
37. implement Binary Search (unique)JavaScript138 accepted
47. reverse a linked list JavaScript Algorithm130 accepted
60. create your own `new` operator JavaScript129 accepted
135. localStorage with expiration JavaScript128 accepted
130. create LazyMan()JavaScript126 accepted
12. implement Immutability helper JavaScript126 accepted
118. Virtual DOM II - createElement JavaScript124 accepted
97. compress a string JavaScript124 accepted
85. implement `_.get()`JavaScript Lodash124 accepted
31. implement async helper - `race()`JavaScript123 accepted
146. implement Array.prototype.reduce()JavaScript122 accepted
122. implement memoizeOne()JavaScript121 accepted
61. create your own `Function.prototype.call`JavaScript117 accepted
53. write your own `extends` in es5 JavaScript117 accepted
55. highlight keywords in HTML string JavaScript Algorithm116 accepted
56. call APIs with pagination JavaScript113 accepted
106. Find two numbers that sum up to 0 JavaScript Algorithm112 accepted
145. most frequently occurring character JavaScript108 accepted
139. implement _.partial()JavaScript Lodash107 accepted
103. implement Math.sqrt()JavaScript Algorithm106 accepted
83. create an interval JavaScript ByteDance105 accepted
66. remove duplicates from an array JavaScript Algorithm103 accepted
133. roman numerals to integer JavaScript101 accepted
125. implement classNames()JavaScript101 accepted
86. Generate Fibonacci Number JavaScript Algorithm100 accepted
152. Find Top k Elements JavaScript Algorithm99 accepted
69. implement deep equal `_.isEqual()`JavaScript Lodash99 accepted
65. add comma to number JavaScript97 accepted
93. Generate Fibonacci Number with recursion JavaScript96 accepted
38. implement `jest.spyOn()`JavaScript96 accepted
59. create a browser history JavaScript95 accepted
79. convert snake_case to camelCase JavaScript94 accepted
120. create `isPrime()`JavaScript Algorithm91 accepted
117. event delegation JavaScript89 accepted
90. write your own `instanceof`JavaScript88 accepted
88. support negative Array index in JavaScript JavaScript88 accepted
119. create a tokenizer JavaScript87 accepted
94. implement your own `Object.create`JavaScript86 accepted
102. validate string of parentheses JavaScript Algorithm84 accepted
100. detect circle in linked list JavaScript Algorithm83 accepted
116. implement Object.is()JavaScript82 accepted
48. search first index with Binary Search(possible duplicate array)JavaScript Algorithm82 accepted
95. implement String.prototype.trim()JavaScript81 accepted
109. implement `Math.pow()`JavaScript Algorithm80 accepted
81. merge sorted arrays JavaScript Algorithm ByteDance79 accepted
140. Virtual DOM III - Functional Component JavaScript78 accepted
54. flatten Thunk JavaScript78 accepted
40. implement Bubble Sort JavaScript Algorithm78 accepted
99. extract all anchor element from HTML string JavaScript77 accepted
27. implement completeAssign() JavaScript73 accepted
132. the angle between hour hand and minute hand of a clock JavaScript U-NEXT72 accepted
36. create a fake timer(setTimeout)JavaScript72 accepted
52. create a middleware system JavaScript71 accepted
87. longest substring with unique characters JavaScript Algorithm70 accepted
70. implement Observable.from()JavaScript70 accepted
136. find median of two sorted array JavaScript Algorithm67 accepted
112. remove duplicate characters in a string JavaScript Algorithm67 accepted
96. count "1" in binary form JavaScript67 accepted
72. implement Observable interval()JavaScript67 accepted
108. Implement a Stack by using Queue JavaScript Algorithm64 accepted
21. implement JSON.stringify()JavaScript63 accepted
137. binary tree vertical traversal JavaScript Algorithm62 accepted
111. Count palindromic substrings JavaScript Algorithm60 accepted
82. find available meeting slots JavaScript Algorithm Airbnb57 accepted
49. search last index with Binary Search(possible duplicate array)JavaScript Algorithm57 accepted
101. merge identical API calls JavaScript56 accepted
43. implement Quick Sort JavaScript Algorithm54 accepted
62. implement BigInt addition JavaScript Algorithm52 accepted
41. implement Merge Sort JavaScript Algorithm52 accepted
149. interpolation JavaScript50 accepted
147. Pick up stones JavaScript50 accepted
134. create your own Cookie JavaScript50 accepted
45. find the K-th largest element in an unsorted array JavaScript Algorithm50 accepted
22. implement JSON.parse()JavaScript49 accepted
42. implement Insertion Sort JavaScript Algorithm47 accepted
80. implement your own URLSearchParams JavaScript46 accepted
73. implement Observable fromEvent()JavaScript46 accepted
50. search element right before target with Binary Search(possible duplicate array)JavaScript Algorithm45 accepted
142. lit-html 1 - tagged templates JavaScript lit-html44 accepted
71. implement Observable Subject JavaScript44 accepted
51. search element right after target with Binary Search(possible duplicate array)JavaScript Algorithm44 accepted
44. implement Selection Sort JavaScript Algorithm41 accepted
74. implement Observable Transformation Operators JavaScript39 accepted
78. convert HEX color to RGBA JavaScript38 accepted
153. uglify CSS class names JavaScript36 accepted
143. Virtual DOM IV - JSX 1 JavaScript34 accepted
84. create a fake timer (setInterval)JavaScript34 accepted
98. validate an IP address JavaScript26 accepted
75. implement BigInt subtraction JavaScript Algorithm26 accepted
124. calculate arithmetic expression JavaScript Algorithm24 accepted
114. implement BigInt multiplication JavaScript14 accepted
76. implement BigInt addition with sign JavaScript11 accepted
115. implement BigInt division JavaScript8 accepted
126. BigDecimal addition JavaScript Algorithm7 accepted
141. implement btoa()JavaScript6 accepted
128. BigDecimal multiplication JavaScript Algorithm6 accepted
150. Virtual DOM V - JSX 2 JavaScript5 accepted
129. BigDecimal Division JavaScript Algorithm4 accepted
77. implement BigInt subtraction with sign JavaScript4 accepted
144. serialize and deserialize data types not supported in JSON JavaScript3 accepted
127. BigDecimal subtraction JavaScript Algorithm2 accepted