collatz.go

package main

import (
"fmt"
"os"
"strconv"
//"time"
)
func linear_collatz(init_num int) {
  num := 0
  count := 0
  highest_number := 0
  highest_count := 0
  for i := 2; i < init_num; i++{
    num = i
    count = 0
    for {
      if num == 1 {
        break
      }

      num1 := 0
      if num%2 == 0 {
        num1 = num/2
      } else {
        num1 = ((3*num)+1)
      }
      num = num1
      count = count + 1
    }
    if count > highest_count {
      highest_count = count
      highest_number = i
    }
  }
  fmt.Println(highest_count)
  fmt.Println(highest_number)
}

func cached_linear_collatz(init_num int) {
  m := make(map[int]int)
  num := 0
  count := 0
  highest_number := 0
  highest_count := 0
  for i := 2; i < init_num; i++{
    num = i
    count = 0
    for {
      if num == 1 {
        m[i] = count
        break
      }

      num1 := 0
      if m[num] != 0 {
        count = count + m[num]
        m[i] = count
        break
      } else {
        if num%2 == 0 {
          num1 = num/2
        } else {
          num1 = ((3*num)+1)
        }
      }
      num = num1
      count = count + 1
    }
    if count > highest_count {
      highest_count = count
      highest_number = i
    }
  }
  fmt.Println(highest_count)
  fmt.Println(highest_number)
}

func main() {
  init_num := 1
  method := ""
  if len(os.Args) == 3 {
    var arg_num, _ = strconv.Atoi(os.Args[1])
    init_num = arg_num
    method = os.Args[2]
  } else if len(os.Args) == 2 {
    var arg_num, _ = strconv.Atoi(os.Args[1])
    init_num = arg_num
  } else {
    fmt.Println("Invalid amount of arguments")
  }

  if method == "" || method == "linear" {
    linear_collatz(init_num)
  } else if method == "cached" {
    cached_linear_collatz(init_num)
  }
}