Exercise 41

    PASS
     f("I am learning Go!") =
      map[string]int{"I":1, "am":1, "learning":1, "Go!":1}
    PASS
     f("The quick brown fox jumped over the lazy dog.") =
      map[string]int{"The":1, "quick":1, "fox":1, "jumped":1, "the":1, "brown":1, "over":1, "lazy":1, "dog.":1}
    PASS
     f("I ate a donut. Then I ate another donut.") =
      map[string]int{"I":2, "ate":2, "a":1, "donut.":2, "Then":1, "another":1}
    PASS
     f("A man a plan a canal panama.") =
      map[string]int{"A":1, "man":1, "a":2, "plan":1, "canal":1, "panama.":1}

    Program exited.