多个空格用一个空格替代

#include <stdio.h>

int main()
{
int c;
int lastc = 'a';
c = getchar();
while(c != EOF)
{
if(c != ' ')
{
putchar(c);
lastc = c;
c = getchar();
}
else
{
if(lastc != ' ')
putchar(c);
lastc = c;
c = getchar();
}
}
return 0;
}