Problem #2

Problem link
Solution:

package main

func main() {
    a, b, sum := 1, 2, 0
    for b < 4000000 {
        if b%2 == 0 {
            sum += b
        }
        a, b = b, a+b
    }
    println(sum)
}

Result: 4613732
Time: 0m0.003s

Problem #25

Problem link
Solution:

package main

import (
    "big"
)

func main() {
    a, b, c, counter := big.NewInt(int64(1)), big.NewInt(int64(2)), big.NewInt(int64(0)), 2
    for len(a.String()) < 1000 {
        c.Neg(a) //c is a temp variable
        a.Add(a, b)
        b.Neg(c)
        counter++
    }
    println(counter)
}

Result: 4782
Time: 0m2.108s