What is the sum of first 50 numbers?

What is the sum of first 50 numbers?

And hence the sum of the first 50 natural numbers to be 1275.

How do I sum in Numpy?

numpy. sum() in Python

1. Parameters :
2. arr : input array.
3. axis : axis along which we want to calculate the sum value. Otherwise, it will consider arr to be flattened(works on all the axis).
4. out : Different array in which we want to place the result.
5. initial : [scalar, optional] Starting value of the sum.

How do you reverse an element in an array in Python?

6. Python program to print the elements of an array in reverse order

1. STEP 1: Declare and initialize an array.
2. STEP 2: Loop through the array in reverse order that is, the loop will start from (length of the array – 1) and end at 0 by decreasing the value of i by 1.
3. STEP 3: Print the element arr[i] in each iteration.

How to find the sum of pairs in an array?

We can iterate over all the pairs of the given array, and then count the pairs whose sum is equal to K. Initialize a variable answer=0. If arr [i]+arr [j] is equal to k, then increament answer by 1.

How to find the number of pairs with sum k?

Input: N = 4, X = 2 arr [] = {1, 1, 1, 1} Output: 6 Explanation: Each 1 will produce sum 2 with any 1. You don’t need to read input or print anything. Your task is to complete the function getPairsCount () which takes arr [], n and k as input parameters and returns the number of pairs that have sum K.

How to subtract arr from sum in C + +?

Expression, sum – arr [n] which yields the value stored in the nth position of the array. Here, the value of arr at n (here at the position where i points, since it is arr [i]) is subtracted with the value of sum.

What happens when you divide count by 2?

After completion of second traversal, we’d have twice the required value stored in counter because every pair is counted two times. Hence divide count by 2 and return. Below is the implementation of above idea :