0012 - Project Euler

// 0012.go contains some functions to solve ProjectEuler.net's Problem #12
// https://projecteuler.net/problem=12
package main

import "fmt"

// CountDivisors returns the count of possible divisors of a given number,
// including 1 and itself.
func CountDivisors(number int) int {
    count := 0
    max := number/2

    for i := 1; i < max; i++ {
        if number%i == 0 {
            // Increase count by itself + value (number / i)
            count += 2;

            // Update max number
            max = number / i
        }
    }

    // Return count
    return count
}

// FirstTriangularNumber returns the first triangular number with more
// that the given number of divisors.
func FirstTriangularNumber(numDivisors int) int {
    triangularnumber := 0
    count := 0

    for i := 1; count <= numDivisors; i++ {
        // Generate triangular number
        triangularnumber += i

        // Update divisor count to divisors in current triangular number
        count = CountDivisors(triangularnumber)
    }

    // Return triangular number
    return triangularnumber
}

func main(){
    // Display result
    fmt.Println(FirstTriangularNumber(500))
}