17-2-4 统计单词个数的错误程序

#include<iostream>
using namespace std;
int pwordnum(char *str);
int main()
{
char str[]="I want to become free.I love freedom!";
cout<<"字符串的单词个数为: "<<pwordnum(str)<<endl;
return 0;
}

int pwordnum(char *str)
{
int j=0;
while(*(str++)!='\0')
if(*(str++)<'A'||(*(str++)>'Z'&&*(str++)<'a')||*(str++)>'z')
j++;
return j;
}