A repository for all my Daily Coding Problem anwsers.
✅ - Completed
This problem was asked by Google.
Given a string, return the first recurring character in it, or null if there is no recurring character.
For example, given the string "acbbac", return "b". Given the string "abcdef", return null.
This problem was asked by Google.
Given a linked list, sort it in O(n log n) time and constant space.
For example, the linked list 4 -> 1 -> -3 -> 99 should become -3 -> 1 -> 4 -> 99.
This problem was asked by Stripe.
Write a function to flatten a nested dictionary. Namespace the keys with a period.
For example, given the following dictionary:
{
"key": 3,
"foo": {
"a": 5,
"bar": {
"baz": 8
}
}
}
it should become:
{
"key": 3,
"foo.a": 5,
"foo.bar.baz": 8
}
You can assume keys do not contain dots in them, i.e. no clobbering will occur.
This problem was asked by Facebook.
Suppose you are given two lists of n points, one list p1, p2, ..., pn on the line y = 0 and the other list q1, q2, ..., qn on the line y = 1. Imagine a set of n line segments connecting each point pi to qi. Write an algorithm to determine how many pairs of the line segments intersect.
This problem was asked by Amazon.
Given an array and a number k that's smaller than the length of the array, rotate the array to the right k elements in-place.
This problem was asked by Palantir.
Write a program that checks whether an integer is a palindrome. For example, 121 is a palindrome, as well as 888. 678 is not a palindrome. Do not convert the integer into a string.
This problem was asked by Uber.
Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand. Find the minimum element in O(log N) time. You may assume the array does not contain duplicates.
For example, given [5, 7, 10, 3, 4], return 3.
This problem was asked by Triplebyte.
Implement a data structure which carries out the following operations without resizing the underlying array:
add(value): Add a value to the set of values.check(value): Check whether a value is in the set.
The check method may return occasional false positives (in other words, incorrectly identifying an element as part of the set), but should always correctly identify a true element.
This problem was asked by Two Sigma.
A knight is placed on a given square on an 8 x 8 chessboard. It is then moved randomly several times, where each move is a standard knight move. If the knight jumps off the board at any point, however, it is not allowed to jump back on.
After k moves, what is the probability that the knight remains on the board?
This problem was asked by Amazon.
Given a linked list, remove all consecutive nodes that sum to zero. Print out the remaining nodes.
For example, suppose you are given the input 3 -> 4 -> -7 -> 5 -> -6 -> 6. In this case, you should first remove 3 -> 4 -> -7, then -6 -> 6, leaving only 5.
This problem was asked by Palantir.
You are given a list of N numbers, in which each number is located at most k places away from its sorted position. For example, if k = 1, a given element at index 4 might end up at indices 3, 4, or 5.
Come up with an algorithm that sorts this list in O(N log k) time.
This problem was asked by Oracle.
Given a binary search tree, find the floor and ceiling of a given integer. The floor is the highest element in the tree less than or equal to an integer, while the ceiling is the lowest element in the tree greater than or equal to an integer.
If either value does not exist, return None.
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent