Create Sumofsquareofnnumbers.py

Sumofsquareofnnumbers.py

@@ -0,0 +1,30 @@
+'''
+Given a positive integer N. The task is to find 12 + 22 + 32 + ….. + N2.
+if N = 4 
+1^2 + 2^2 + 3^2 + 4^2 = 30
+The idea is to run a loop from 1 to n and for each i, 1 <= i <= n, find i2 to sum.
+'''
+
+def squaresum(n):
+	sum = 0
+	for i in range(1, n+1):
+		sum += (i * i)
+	return sum
+
+n = int(input("Enter Number to Print Sum Of square of N Natural Number :\n"))
+print(squaresum(n))
+
+
+'''
+The above approach takes linear time to compute the squaresum however we can solve
+this in constant time using the formula:
+    Σn^2 = [n(n+1)(2n+1)]/6
+Source : https://en.wikipedia.org/wiki/Square_pyramidal_number
+'''
+
+def squaresum(n):
+	sum = (n*(n+1)*(2*n+1))//6
+	return sum
+
+n = int(input("Enter Number to Print Sum Of square of N Natural Number :\n"))
+print(squaresum(n))