Problems
November 21, 2022
Base 7
We will divide the number by 7 and keep track of the remainder. We will add the remainder to the result and multiply the result by 10. We will repeat this process until the number is 0. Time...
ReadNovember 21, 2022
Vowel spellchecker
We will use a set to store the words in the wordlist. Then, we will use a dictionary to store the words in the wordlist with the vowels replaced with *. Then, we will iterate through the...
November 21, 2022
design linked list
We will use a stack to store the values and then do the operations on the stack.
ReadNovember 21, 2022
Total cost to hire k workers
We will sort the workers by their quality and iterate through them. For each worker, we will add their wage to the heap and remove the highest wage if the heap size is greater than k. We...
November 21, 2022
Sum of absolute differences in a sorted array
The absolute difference between two numbers a and b is:
a - b: When a is greater than or equal to b.
b - a: When a is less than or equal to b.
These cases overlap when a...
November 20, 2022
Number of orders in the backlog
We will use two heaps to keep track of the buy and sell orders. The buy orders will be stored in a max heap and the sell orders will be stored in a min heap. We will also keep track of the total...
ReadNovember 20, 2022
Find all duplicates in an array
We will count the frequency of each number in the array, and return the numbers that appear twice.
Time complexity: O(n)
Space complexity: O(n)
November 20, 2022
Widest vertical area between two points containing no points
We sort the points by x-coordinate, and find the maximum distance between two consecutive points.
Time complexity: O(nlogn)
Space complexity: O(n)
November 20, 2022
Shopping offers
We can use DFS with memoization to solve this problem. We will keep track of the current state of the shopping list. Then we will iterate over each offer and we will check if the offer is valid. If...
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Reverse prefix of word
We will iterate through the word and check if the current character is equal to the first character of the prefix. If it is, we will reverse the prefix and return the word. Time complexity:...
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