c语言：输入一行字符，统计其中的单词个数，单词之间用空格分开

#include<stdio.h>
int main()
{
int  = 0, word = 0, i = 0;
char str[40];
gets(str);
while(str[i] != '\0')
{
if(str[i] == ' ')
{
word = 0;
}
else
{
if(0 == word)
{
++;
word = 1;
}
else
{
word = 1;
}
}
i++;
}
printf("%d\n",);
return 0;
}