Delete the blank characters at the beginning and end of the string, and convert (merge) Multiple spaces (if any) in the middle of the array into one.

This is an interview question:

Delete the blank characters at the beginning and end of the string, and convert (merge) Multiple spaces in the middle of the array into one. For example! "Changed to" I like python! ".

The problem is clear. The key is to reduce the number of characters to move. To reduce the number of characters to be moved, you can just move the characters to an accurate position at a time. Do not move unnecessary characters. The following provides some simple Python code.

#!/usr/bin/pythonimport sysdef rmblank(blankstr):        new_start=0        i=0        blankspace=False        while i<len(blankstr):                #move behind chars to new start point                if blankstr[i]!=' ':                        blankstr[new_start]=blankstr[i]                        new_start+=1                        blankspace=True                else:                        #if more than one blank, move behind chars to new start point                        if blankspace==True:                                blankstr[new_start]=blankstr[i]                                new_start+=1                                blankspace=False                i+=1        return blankstr[0:new_start]def main():        blankstr=" I like   python   ! "        print blankstr        print ''.join(rmblank(list(blankstr)))if __name__=='__main__':        main()

References:

Jude Zou's http://www.oschina.net/code/snippet_142087_4696