Conditional Loop through All Values based on First Value

Question

Okay,

So I am having a bit of an issue phrasing this question. Perhaps it's easier to present an example:

Suppose we consider the four seasons: Winter, Spring, Summer and Fall (in that particular order). And suppose now that we have the following text:

I love the Summer.
The Winter is not a good season. 
Spring brings more joy. 
And Fall is the best.

Now, suppose I have a program that reads the file, and upon encountering the first season (in this case, Summer) replaces all other seasons with the first instance. Then, it prints out the text again, this time with the next season, repeatedly, until all seasons have been covered.

For example, the above text should produce the following output:

//..Replace with 'Summer'
I love the Summer.
The Summer is not a good season. 
Summer brings more joy. 
And Summer is the best. 
//.. Replace with 'Winter'
I love the Winter.
The Winter is not a good season. 
Winter brings more joy. 
And Winter is the best.
//.. Replace with 'Spring'
I love the Spring.
The Spring is not a good season. 
Spring brings more joy. 
And Spring is the best.
//.. Replace with 'Fall'
I love the Fall.
The Fall is not a good season. 
Fall brings more joy. 
And Fall is the best.

Now, however, if the poem had read:

I love the Fall.
The Winter is not a good season. 
Spring brings more joy. 
And Summer is the best.

The program would start by replacing every instance of a season with "Fall", and then do the same for Winter, Spring and Summer. (Since Winter, Spring, Summer, Fall) is the default order.

In short: the first season encountered is defines the first iteration of he "replace" action. That is, if "Summer" is encountered, the entire text has its seasons replaced with Summer. Then with Winter, Spring and Fall. If "Spring" is encountered first, the text first replaces all the seasons with "Spring", then Winter, Summer, and Fall.

I know one could do this by writing a a series of conditional statements, such as:

if summer
  replace summer
  replace winter
  replace spring
  replace fall

else if spring
  replace spring
  replace winter
  replace summer
  replace fall

else if winter
  replace winter
  replace spring
  replace summer
  replace fall

else if fall
  replace fall
  replace winter
  replace spring
  replace summer

However, this hardly seems the best way to do so. I know the text has to be replaced with all seasons at some point. I also know that the order of these seasons. The only thing that matters is the first season instance, which then determines which season is to be taken out from its place, and put in front.

If this question made any sense at all, I would highly appreciate some advice. I'm not particularly looking for code, but rather for tips on how to approach such a question.

Thanks guys.

score 1 · Accepted Answer · edited May 23 '17 at 12:29

1

The straightforward approach would be:

Extract the words in the order they appear and place them in a List.
Loop through each element in that list.
Inside that loop, loop through every possible word and replace it with the current element from step 2.
Print the result.

I don't do much Java, but here is an answer about replacing multiple strings which may be useful.

edited May 23 '17 at 12:29

Community

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answered Sep 23 '14 at 12:15

Dark Falcon

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score 0 · Answer 2 · answered Sep 23 '14 at 12:17

One way to do this is by keeping the seasons in a list and reading the list exactly four times.

List iteration begins from the season first encountered
Go back to the beginning if you reach the end of the list before 4 reads

score 0 · Answer 3 · answered Sep 23 '14 at 12:17

You could create ordered list of all seasons (Winter, Spring, Summer, Fall) and then when you encounter first season rearange that list -- in your example list would became (Summer, Fall, Winter, Sprint).

After that all you need to do is to iterate over rearanged list and replace text as you said.

Conditional Loop through All Values based on First Value

3 Answers3