Day 08 - Least Square Regression Line.py

# ========================
#       Information
# ========================

# Direct Link: https://www.hackerrank.com/challenges/s10-least-square-regression-line/problem
# Difficulty: Easy
# Max Score: 30
# Language: Python

# ========================
#         Solution
# ========================

def mean(X):
    '''To calculate the mean'''
    return sum(X)/len(X)

def lsr(X, Y):
    '''To calculate the Least Square Regression'''
    B = sum([(X[i] - mean(X)) * (Y[i] - mean(Y))
             for i in range(len(X))])/sum([(j - mean(X))**2 for j in X])
    A = mean(Y) - (B*mean(X))
    return A+(B*80)

X = []
Y = []

for i in range(5):
    A, B = list(map(int, input().split()))
    X.append(A)
    Y.append(B)

print(round(lsr(X, Y), 3))