How to remove spaces that are in a string sentence

Question

I am trying to write a code to remove all the leading, trailing and middle of the sentence spaces but to keep only one space between the words.

For example if the input

Answer 1

Use two pointers. The first points at the next character to read, and the second points at the location to write.

If you read two spaces in a row, don't advance the write pointer.

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Another approach you may want to consider is to use strtok with " " as a delimiter.