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

You could have two arrays and two counters. Each iteration you always increase your first counter, but only increase your second when the character is not a space. A table of it would look like this.

  Char   In-Pos  Out-Pos

   ' '      0      0
   ' '      1      0
   ' '      2      0
   ' '      3      0
   'T'      4      0
   'h'      5      1
   'i'      6      2
   's'      7      3
   ' '      8      4
   ' '      9      5
   ' '     10      5
   ' '     11      5
   'i'     12      5
   's'     13      6
   ' '     14      7
   'm'     15      8
   'y'     16      9
   ' '     17     10
   ' '     18     11
   ' '     19     11
   ' '     20     11
   ' '     21     11
   's'     22     11
   't'     23     12
   'r'     24     13
   'i'     25     14
   'n'     26     15
   'g'     27     16
   ' '     28     17
   ' '     29     18
   ' '     30     18
   ' '     31     18