#include<
stdio.h>
int main()
{
char sentence[200],*p;
gets(sentence);
p=sentence;
if(*p>='a'&&*p<='z') *p=*p-32;
while(*++p!='\0')
{
if(*(p-1)==' '||*(p-1)=='.'||*(p-1)=='?'||*(p-1)=='!')
{
if(*p>='a'&&*p<='z') *p-=32;
}
else if(*p>='A'&&*p<='Z') *p+=32;
}
puts(sentence);
return 0;
}本回答被提问者采纳