Solution to Problem 12

Project Euler/Problem 12/sol1.py

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+from __future__ import print_function
+from math import sqrt
+'''
+Highly divisible triangular numbers
+Problem 12
+The sequence of triangle numbers is generated by adding the natural numbers. So the 7th triangle number would be 1 + 2 + 3 + 4 + 5 + 6 + 7 = 28. The first ten terms would be:
+
+1, 3, 6, 10, 15, 21, 28, 36, 45, 55, ...
+
+Let us list the factors of the first seven triangle numbers:
+
+ 1: 1
+ 3: 1,3
+ 6: 1,2,3,6
+10: 1,2,5,10
+15: 1,3,5,15
+21: 1,3,7,21
+28: 1,2,4,7,14,28
+We can see that 28 is the first triangle number to have over five divisors.
+
+What is the value of the first triangle number to have over five hundred divisors?
+'''
+try:
+	xrange		#Python 2
+except NameError:
+	xrange = range	#Python 3
+
+def count_divisors(n):
+	nDivisors = 0
+	for i in xrange(1, int(sqrt(n))+1):
+		if n%i == 0:
+			nDivisors += 2
+
+	return nDivisors
+
+tNum = 1
+i = 1
+
+while True:
+	i += 1
+	tNum += i
+
+	if count_divisors(tNum) > 500:
+		break
+
+print(tNum)