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Even Fibonacci numbers

1 min  

over 1 year ago

 30/04/2019 

Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:

1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...

By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.

package main

import (
   "fmt"
   "time"
)

func main()
  {
   start := time.Now()

   i, c, sum := [...]int{1, 1}, 0, 0
   for c < 4e6 {
      c = i[0] + i[1]
      i[0] = i[1]
      i[1] = c
      if c % 2 == 0 {
         sum += c
      }
   }
   fmt.Println("Execution time: ", time.Since(start))
   fmt.Print(sum)
}

Execution time: 276ns

Answer: 4613732