Interview Question : Trim multiple consecutive spaces from a string

Question

This is an interview question Looking for best optimal solution to trim multiple spaces from a string. This operation should be in-place operation.

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Answer 1

Keep two indices: The next available spot to put a letter in (say, i), and the current index you're examining (say, j).

Just loop over all the characters with j, and whenever you see a letter, copy it to index i, then increment i. If you see a space that was not preceded by a space, also copy the space.

I think this would work in-place...