字符处理练习——C/C++

//输入某字符串，以#结束。输出的字符串要满足以下要求：删除元音，辅音前加. ，大小写互换。
#include<stdio.h>
#include<string.h>
int main()
{
    char s[100],res[100];
    int sn=0,resn=0;
    char c;
    while((c=getchar())&&c!='#'){
        s[sn++] = c;
    } 
    s[sn] = '\0';
    int i = 0;
    while(s[i]!='\0'){
        if(s[i]=='A'||s[i]=='a'||s[i]=='E'||s[i]=='e'||s[i]=='I'||s[i]=='i'||
           s[i]=='O'||s[i]=='o'||s[i]=='U'||s[i]=='u'){
                   ;
           }
        else if(s[i]>'A'&&s[i]<'Z'){
            res[resn++] = '.';
//          res[resn++] = tolower(s[i]);
            res[resn++] = s[i]+('a'-'A');
        }else if(s[i]>'a'&&s[i]<'z'){
            res[resn++] = '.';
//          res[resn++] = toupper(s[i]);
            res[resn++] = s[i]-('a'-'A');
        }else{
            res[resn++] = s[i];
        }
        i++;
    }
    res[resn] = '\0';
    puts(res);
    
    return 0;
}