HackerRank Dot and Cross problem solution in Python

HackerRank Dot and Cross problem solution in Python – In this Dot and Cross problem, you are given two arrays A and B. Both have dimensions of N X M. Your task is to compute their matrix product.

dot

The dot tool returns the dot product of two arrays.

import numpy

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

print numpy.dot(A, B)       #Output : 11

cross

The cross tool returns the cross product of two arrays.

import numpy

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

print numpy.cross(A, B)     #Output : -2

HackerRank Dot and Cross problem solution in Python 2.

import numpy
a=int(raw_input())
m=[]
n=[]
for i in range(a):
    m.append(map(int,raw_input().split()))
for i in range(a):
    n.append(map(int,raw_input().split()))
print numpy.dot(numpy.array(m),numpy.array(n))

Dot and Cross problem solution in Python 3.

import numpy
n=int(input())
a = numpy.array([input().split() for _ in range(n)],int)
b = numpy.array([input().split() for _ in range(n)],int)
m = numpy.dot(a,b)
print (m)

Problem solution in pypy programming.

# Enter your code here. Read input from STDIN. Print output to STDOUT
import numpy
n=int(raw_input().strip())
a=[]
b=[]
for i in xrange(n):
    t=map(int,raw_input().split())
    a.append(t)
for i in xrange(n):
    t=map(int,raw_input().split())
    b.append(t)
a=numpy.matrix(a)
b=numpy.matrix(b)
print a*b

Problem solution in pypy3 programming.

# Enter your code here. Read input from STDIN. Print output to STDOUT
import numpy as np
n= int(input())
a = np.array([input().split() for _ in range(n)],dtype=np.int)
b = np.array([input().split() for _ in range(n)],dtype=np.int)

res = []
for r in range(n):
    row = [np.dot(a[r,:],b[:,i]) for i in range(n)]
    res.append(row)

res = np.array(res)
print(res)