How do you find the number of subarrays in an array?

The number of all possible subarrays of an array of size N is N * (N + 1)/2. Let countSubarrays(N) = N * (N + 1)/2.

How do you find the GCD of a range of numbers?

GCD of elements in a given range

1. if a = b : the segment consists of a single number, hence the answer is a.
2. if a < b : we have gcd(n, n + 1, n?+ 2, …, m) = gcd(gcd(n, n + 1), n + 2, …, m) = gcd(1, n + 2, …, n) = 1.

How many Subarrays are in an array Java?

A set of size ‘n’ can have a total of [n*(n+1)] / 2 subsets. Let the array be [1,2,3]. Subarrays are contiguous elements i.e 1,2,3,12,23,123 here. For n =3 , total number of subsets / subarrays are 6 ( [3* 4] / 2).

What is the GCD of 8 and 12?

4
Answer: GCF of 8 and 12 is 4.

How do you find the gcd of a list in Python?

import functools as f A = [12, 24, 27, 30, 36] g = lambda a,b:a if b==0 else g(b,a\%b) #Gcd for two numbers print(f. reduce(lambda x,y:g(x,y),A)) #Calling gcd function throughout the list.

How to find sum of all the GCDs of all subarrays?

How to find sum of all the GCDs of all the subarrays of an array? Given an array A of length n = 10^5. I have to find the sum of GCD of all subarrays of this array efficiently. The first thing that should be marked is that GCD (A [i-1 : j]) * d = GCD (A [i : j]) where d is natural number.

What is the GCD of a subarray of length k?

A subarray of length k is constructed from subarray of length k-1 + 1 element. So GCD of subarray including k’th element is GCD of k’th element and GCD of subarray of k-1 elements i.e. GCD (GCD (A [i:i+k],A [k]).

How to find all possible subarrays of an array efficiently?

How to find all possible subarrays of an array efficiently? We can use substr function to find the all possible sub array.

How to quickly find blocks with equal GCD in R?

To fastly find blocks with equal GCD you can use a segment tree. To find a block you just need to find the longest subarray ending in fixed element, where gcd is smaller, then on your previously checked block. To do it just binary search this index and check condition using queries in the segment tree.