题解 | #字符串加解密#

#include<stdio.h>
#include<string.h>
int main()
{
    char a[1000], b[1000];
    gets(a);
    gets(b);
    for(int i=0; i<strlen(a); i++)
    {
        if(isalpha(a[i]))
        {
            if(a[i]>='A' && a[i]<'Z')
                a[i] += 33;
            else if(a[i] == 'Z')
                a[i] = 'a';
            else if(a[i]>='a' && a[i]<'z')
                a[i] -= 31;
            else if(a[i] == 'z')
                a[i] = 'A';
        }
        else
        {
            if(a[i] == '9')
                a[i] = '0';
            else
                a[i] += 1;
        }
    }
    for(int i=0; i<strlen(b); i++)
    {
        if(isalpha(b[i]))
        {
            if(b[i]>'A' && b[i]<='Z')
                b[i] += 31;
            else if(b[i] == 'A')
                b[i] = 'z';
            else if(b[i]>'a' && b[i]<='z')
                b[i] -= 33;
            else if(b[i] == 'a')
                b[i] = 'Z';
        }
        else
        {
            if(b[i] == '0')
                b[i] = '9';
            else
                b[i] -= 1;
        }
    }
    printf("%s\n", a);
    printf("%s\n", b);
}