Código claro

    #include <stdio.h>
    #include <string.h>

    enum
    {
        DESPL = 10,
        ASC_ESPACIO = 32,
        ASC_Z = 122
    };

    int main(void)
    {
        int i; int c;
        char s[] = "Codigo claro";

        for (i=0; i < strlen(s); i++)
        {
            c = s[i] + DESPL;
            if (c > ASC_Z)
                c = c - ASC_Z + ASC_ESPACIO;
            printf("%c", c);
        }
        return 0;
    }