| // Copyright 2023 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package main |
| |
| import ( |
| "fmt" |
| "os" |
| ) |
| |
| func main() { |
| x := f(60) |
| fmt.Println(x) |
| if x != 54 { |
| os.Exit(11) |
| } |
| } |
| |
| var escape *int |
| |
| func f(i int) int { |
| a := 0 |
| outer: |
| for { |
| switch { |
| case i > 55: |
| i-- |
| continue |
| case i == 55: |
| for j := i; j != 1; j = j / 2 { |
| a++ |
| if j == 4 { |
| escape = &j |
| i-- |
| continue outer |
| } |
| if j&1 == 1 { |
| j = 2 * (3*j + 1) |
| } |
| } |
| return a |
| case i < 55: |
| return i |
| } |
| } |
| } |