HackerRank Python Solution - Numpy Topic - Sum and Prod

Sum:

The sum tool returns the sum of array elements over a given axis.

import numpy

my_array = numpy.array([ [1, 2], [3, 4] ])

print numpy.sum(my_array, axis = 0)         #Output : [4 6]
print numpy.sum(my_array, axis = 1)         #Output : [3 7]
print numpy.sum(my_array, axis = None)      #Output : 10
print numpy.sum(my_array)                   #Output : 10

By default, the axis value is None. Therefore, it performs a sum over all the dimensions of the input array. 

Prod:

The prod tool returns the product of array elements over a given axis.

import numpy

my_array = numpy.array([ [1, 2], [3, 4] ])

print numpy.prod(my_array, axis = 0)            #Output : [3 8]
print numpy.prod(my_array, axis = 1)            #Output : [ 2 12]
print numpy.prod(my_array, axis = None)         #Output : 24
print numpy.prod(my_array)                      #Output : 24

By default, the axis value is None. Therefore, it performs the product over all the dimensions of the input array.

Task:

You are given a 2-D array with dimensions N x M. Your task is to perform the sum tool over axis 0 and then find the product of that result.

Input Format:

The first line of input contains space-separated values of N and M. The next N lines contain M space-separated integers.

Output Format:

Compute the sum along axis 0. Then, print the product of that sum.

Sample Input:

2 2
1 2
3 4

Sample Output:

24

Explanation:

The sum along axis 0 = [4 6] The product of this sum = 24

Solution:

import numpy as np

n,m = map(int,input().split())

arr = np.array([input().split() for _ in range(n)],int)

print(np.prod(np.sum(arr, axis=0)))

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