Step by Step solution about How to resolve the algorithm Old lady swallowed a fly step by step in the Kotlin programming language

Kotlin Program to Solve the Rhyme “There was an Old Lady who Swallowed a Fly”

In this program, the rhyme "There was an Old Lady who Swallowed a Fly" is implemented using Kotlin language. This code takes the animals and phrases from the rhyme and presents them in the correct order. Let's break down the code step by step:

1. Data Initialization:

   • Two lists named animals and phrases are defined. These lists contain the animals and phrases used in the rhyme, respectively.

2. sing() Function:

   • The sing() function forms the core of the program and is responsible for printing the rhyme. It iterates through each animal in the animals list and prints the corresponding phrase from the phrases list.
   • For each animal, it checks if it is the first animal (index i is 0). If not, it prints the exclamation mark after the phrase.
   • If it's the last animal (index i is 7), it returns early to terminate the loop.
   • Before moving to the next animal, it prints the lines that describe the old lady swallowing the previous animals to catch the current one. This loop runs from i down to 1 (inclusive).
   • It then prints the final line of the verse.

3. main() Function:

   • The main() function is the entry point of the program. It simply calls the sing() function to execute the rhyme.

Output:

When you run the program, it will print the following output:

There was an old lady who swallowed a fly;
I don't know why she swallowed a fly - Perhaps she'll die!

There was an old lady who swallowed a spider;
That wriggled and jiggled and tickled inside her!
She swallowed the spider to catch the fly;
I don't know why she swallowed a fly - Perhaps she'll die!

There was an old lady who swallowed a bird;
How absurd to swallow a bird!
She swallowed the bird to catch the spider,
That wriggled and jiggled and tickled inside her!
She swallowed the spider to catch the fly;
I don't know why she swallowed a fly - Perhaps she'll die!

There was an old lady who swallowed a cat;
Fancy that to swallow a cat!
She swallowed the cat to catch the bird,
How absurd to swallow a bird!
She swallowed the bird to catch the spider,
That wriggled and jiggled and tickled inside her!
She swallowed the spider to catch the fly;
I don't know why she swallowed a fly - Perhaps she'll die!

There was an old lady who swallowed a dog;
What a hog, to swallow a dog!
She swallowed the dog to catch the cat,
Fancy that to swallow a cat!
She swallowed the cat to catch the bird,
How absurd to swallow a bird!
She swallowed the bird to catch the spider,
That wriggled and jiggled and tickled inside her!
She swallowed the spider to catch the fly;
I don't know why she swallowed a fly - Perhaps she'll die!

There was an old lady who swallowed a goat;
She just opened her throat and swallowed a goat!
She swallowed the goat to catch the dog,
What a hog, to swallow a dog!
She swallowed the dog to catch the cat,
Fancy that to swallow a cat!
She swallowed the cat to catch the bird,
How absurd to swallow a bird!
She swallowed the bird to catch the spider,
That wriggled and jiggled and tickled inside her!
She swallowed the spider to catch the fly;
I don't know why she swallowed a fly - Perhaps she'll die!

There was an old lady who swallowed a cow;
I don't know how she swallowed a cow!
She swallowed the cow to catch the goat,
She just opened her throat and swallowed a goat!
She swallowed the goat to catch the dog,
What a hog, to swallow a dog!
She swallowed the dog to catch the cat,
Fancy that to swallow a cat!
She swallowed the cat to catch the bird,
How absurd to swallow a bird!
She swallowed the bird to catch the spider,
That wriggled and jiggled and tickled inside her!
She swallowed the spider to catch the fly;
I don't know why she swallowed a fly - Perhaps she'll die!

...She's dead of course!

// version 1.1.3

val animals = listOf("fly", "spider", "bird", "cat","dog", "goat", "cow", "horse")

val phrases = listOf(
    "",
    "That wriggled and jiggled and tickled inside her",
    "How absurd to swallow a bird",
    "Fancy that to swallow a cat",
    "What a hog, to swallow a dog",
    "She just opened her throat and swallowed a goat",
    "I don't know how she swallowed a cow",
    "\n  ...She's dead of course"
)

fun sing() {
    for (i in 0..7) {
       println("There was an old lady who swallowed a ${animals[i]};")
       if (i > 0) println("${phrases[i]}!")
       if (i == 7) return
       println()                  
       if (i > 0) {
           for (j in i downTo 1) {
               print("  She swallowed the ${animals[j]} to catch the ${animals[j - 1]}")
               println(if (j < 3) ";" else ",")
               if (j == 2) println("  ${phrases[1]}!")               
           }
       }
       println("  I don't know why she swallowed a fly - Perhaps she'll die!\n")
    }
}  

fun main(args: Array<String>) {
    sing()
}