# Papildomos užduotys

# Vaizdo pamoka

# Daily Coding Problem

Eikite adresu dailycodingproblem.com (opens new window) ir prenumeruokite užduotis.

Kiekvieną dieną į pašto dėžutę gausite po programavimo problemą iš tokių organizacijų kaip Google, Facebook, Airbnb ir t.t.

Spręskite gautas užduotis. Taip tobulėsite kiekvieną dieną.

Taip pat, galima nusipirkti knygą su užduotimis ir jų sprendimais. Daugiau informacijos rasite čia (opens new window).

Kelios pavyzdinės užduotys, gaunamos iš Daily Coding Problem pateiktos žemiau.

# Pavyzdinė užduotis 1

This problem was recently asked by Google.

Given a list of numbers and a number k, return whether any two numbers from the list add up to k.

For example, given [10, 15, 3, 7] and k of 17, return true since 10 + 7 is 17.

Bonus: Can you do this in one pass?

# Pavyzdinė užduotis 2

This problem was asked by Uber.

Given an array of integers, return a new array such that each element at index i of the new array is the product of all the numbers in the original array except the one at i.

For example, if our input was [1, 2, 3, 4, 5], the expected output would be [120, 60, 40, 30, 24]. If our input was [3, 2, 1], the expected output would be [2, 3, 6].

Follow-up: what if you can't use division?

# Pavyzdinė užduotis 3

This problem was asked by Stripe.

Given an array of integers, find the first missing positive integer in linear time and constant space. In other words, find the lowest positive integer that does not exist in the array. The array can contain duplicates and negative numbers as well.

For example, the input [3, 4, -1, 1] should give 2. The input [1, 2, 0] should give 3.

You can modify the input array in-place.

# Pavyzdinė užduotis 4

This problem was asked by Facebook.

Given the mapping a = 1, b = 2, ... z = 26, and an encoded message, count the number of ways it can be decoded.

For example, the message '111' would give 3, since it could be decoded as 'aaa', 'ka', and 'ak'.

You can assume that the messages are decodable. For example, '001' is not allowed.

# Pavyzdinė užduotis 5

This problem was asked by Airbnb.

Given a list of integers, write a function that returns the largest sum of non-adjacent numbers. Numbers can be 0 or negative.

For example, [2, 4, 6, 2, 5] should return 13, since we pick 2, 6, and 5. [5, 1, 1, 5] should return 10, since we pick 5 and 5.

Follow-up: Can you do this in O(N) time and constant space?

# Pavyzdinė užduotis 6

This problem was asked by Amazon.

There exists a staircase with N steps, and you can climb up either 1 or 2 steps at a time. Given N, write a function that returns the number of unique ways you can climb the staircase. The order of the steps matters.

For example, if N is 4, then there are 5 unique ways:

  • 1, 1, 1, 1
  • 2, 1, 1
  • 1, 2, 1
  • 1, 1, 2
  • 2, 2

What if, instead of being able to climb 1 or 2 steps at a time, you could climb any number from a set of positive integers X? For example, if X = {1, 3, 5}, you could climb 1, 3, or 5 steps at a time.