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

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.

How do you find the number of distinct numbers in an array?

Algorithm

1. Start.
2. Declare an array.
3. Initialize the array.
4. Call a function to count the distinct elements.
5. Declare a count variable and initialize it to 1.
6. Declare two for loops.
7. Use the first for loop to fix one array element.
8. Use the second loop to look for duplicate elements in the remaining elements.

What are subarrays of an array?

A subarray is a contiguous part of array. An array that is inside another array. For example, consider the array [1, 2, 3, 4], There are 10 non-empty sub-arrays. The subarrays are (1), (2), (3), (4), (1,2), (2,3), (3,4), (1,2,3), (2,3,4) and (1,2,3,4).

How do you find the longest subsequence in an array?

To find the LIS for a given array, we need to return max(L(i)) where 0 < i < n. Formally, the length of the longest increasing subsequence ending at index i, will be 1 greater than the maximum of lengths of all longest increasing subsequences ending at indices before i, where arr[j] < arr[i] (j < i).

How do you find a distinct number?

Algorithm to print distinct numbers in an array

1. Declare and input the array elements.
2. Traverse the array from the beginning.
3. Check if the current element is found in the array again.
4. If it is found, then do not print that element.
5. Else, print that element and continue.

How do you find unique pairs in a list?

Method 2 (Use Sorting) 1) Initialize count as 0 2) Sort all numbers in increasing order. 3) Remove duplicates from array. 4) Do following for each element arr[i] a) Binary Search for arr[i] + k in subarray from i+1 to n-1. b) If arr[i] + k found, increment count.

How do you get all subarrays of an array?

Generating subarrays using recursion

1. Stop if we have reached the end of the array.
2. Increment the end index if start has become greater than end.
3. Print the subarray from index start to end and increment the starting index.

How to calculate the length of a distinct subarray?

An efficient solution is based on the fact that if we know all elements in a subarray arr [i..j] are distinct, sum of all lengths of distinct element subarrays in this sub array is ( (j-i+1)* (j-i+2))/2. How? the possible lengths of subarrays are 1, 2, 3,……, j – i +1.

How to create array with number of subarrays?

Create an array of pair where each pair store the value of the element of subarray and its index. Sort the pair in increasing order of A [i] and then decreasing order of i. pair [0] has element of index 6. From index 6 we can have two sub-arrays [1] and [1,3]. So ANS = 2; Now take each consecutive pair one by one.

How do you find the largest subarray of an element?

We first find largest subarray (with distinct elements) starting from first element. We count sum of lengths in this subarray using above formula. For finding next subarray of the distinct element, we increment starting point, i and ending point, j unless (i+1, j) are distinct.

What happens if an element is not included in a subarray?

At each step of recurrence relation, the element can either be included in the subarray or not. If the element is not included in the subarray, then simply move to the next index.