Replacing each string of one or more blanks by a single blank
Looks fine to me.  But I would replace 

if (inspace == 0)


with

if (!inspace)


for stylistic reasons. And

if (c != ' ')


with

else 


because there is no need to compare c again: you already know it isn't equal to a space because of the first if statement.

Also the code inside {...} after main should be indented over.