package ProjectEuler; /** * 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? * *

link: https://projecteuler.net/problem=12 */ public class Problem12 { /** Driver Code */ public static void main(String[] args) { assert solution1(500) == 76576500; } /* returns the nth triangle number; that is, the sum of all the natural numbers less than, or equal to, n */ public static int triangleNumber(int n) { int sum = 0; for (int i = 0; i