Array

Types of questions

Find peak (not ordered)

Find rang of something

File	confidence	date	difficulty	note
33. Search in Rotated Sorted Array	🟢	March 02, 2024	-	-
238. Product of Array Except Self	🟢	March 02, 2024	-	-
977. Squares of a Sorted Array	🟢	March 03, 2024	-	-
56. Merge Intervals	🟢	March 03, 2024	-	-
209. Minimum Size Subarray Sum	🟢	March 03, 2024	medium	-
67. Add Binary	🟢	March 04, 2024	-	-
59. Spiral Matrix II	🟡	March 04, 2024	-	-
11. Container With Most Water	🟢	March 07, 2024	-	-
76. Minimum Window Substring	🟢	March 08, 2024	hard	-
36. Valid Sudoku	🟡	March 09, 2024	-	-
271. Encode and Decode Strings	🟢	March 13, 2024	-	-
128. Longest Consecutive Sequence	🟡	March 13, 2024	-	-
981. Time Based Key-Value Store	🟢	March 14, 2024	-	-
875. Koko Eating Bananas	🟢	March 14, 2024	-	-
74. Search a 2D Matrix	🟢	March 14, 2024	medium	-
4. Median of Two Sorted Arrays	🔴	March 14, 2024	hard	-
153. Find Minimum in Rotated Sorted Array	🟢	March 14, 2024	-	-
567. Permutation in String	🟢	March 17, 2024	-	-
424. Longest Repeating Character Replacement	🟢	March 17, 2024	-	-
647. Palindromic Substrings	🟢	March 19, 2024	-	-
57. Insert Interval	🟡	March 20, 2024	-	-
268. Missing Number	🟢	March 20, 2024	-	-
1851. Minimum Interval to Include Each Query	🔴	March 20, 2024	hard	-
53. Maximum Subarray	🟢	March 26, 2024	-	-
48. Rotate Image	🟡	March 27, 2024	medium	-
43. Multiply Strings	🟡	March 27, 2024	medium	-
1004. Max Consecutive Ones III	🟢	March 28, 2024	-	-
658. Find K Closest Elements	🔴	April 25, 2024	medium	Mid pointer is start of the interval, r start at length - 2. Now, compare two values, m and m + k. If m + k is closer, that means, everything before m is outside of consideration. Else, everything beyond m + k is outside of consideration.
34. Find First and Last Position of Element in Sorted Array	🟢	April 25, 2024	medium	Basically the combination of finding the left most and right most index of a number
334. Increasing Triplet Subsequence	🟢	April 27, 2024	medium	If the two values are decreasing, it would reset the first value , and the second value will remain as inf
122. Best Time to Buy and Sell Stock II	🔴	June 03, 2024	medium	Simply one pass to capture all consecutive increasing gaps
6. Zigzag Conversion	🔴🟡🟢	June 05, 2024	medium	Except for the first and last row, other row have one additional value between each step
15. 3 Sum	🟢	June 08, 2024	medium	check left and right pointer when removing the duplicates
833. Find And Replace in String	🔴	June 16, 2024	medium	To sort multiple array with the order of a single array, can use zip, then unzip by taking the transpose (zip(*array))
624. Maximum Distance in Arrays	🔴	July 29, 2024	medium	Keep a global min and max for the previous array values, compare with the new array's max and min to deduce the result range, and updated the global max/min
280. Wiggle Sort	🔴	July 29, 2024	medium	Just make sure even index is smaller the prev, odd index greater than prev, else swap with prev
2334. Subarray With Elements Greater Than Varying Threshold	🔴	September 19, 2024	medium	# Firstly, we can compare the min_value for each sub_array to see if it satisfy the condition

Since threshold is constant, that mean the higher the k is, more likely the current element is greater than that

Hence find the longest sub_array for each element such that the element is the minimum |