新的C难题，对我而言

Question

将一行电文进行加密，规则为a->d，b->e，c->f……非字母字符不变。要求：编写程序，将原文加密为密文，同时输出原文和密文。

Answer 1

#include <stdio.h>
#include <string.h>
int main()
{
  int i, len;
  char s[1024], s1[1024];
  gets(s);
  len = strlen(s);
  for (i = 0; i < len; i++)
    {
      if ((s[i] >= 'A' && s[i] <= 'W') || (s[i] >= 'a' && s[i] <= 'w'))
        s1[i] = s[i] + 3;
      else if ((s[i] >= 'X' && s[i] <= 'Z') || (s[i] >= 'x' && s[i] <= 'z'))
        s1[i] = s[i] - 23;
      else
        s1[i] = s[i];
    }
  s1[len] = '\0';
  printf("原文:%s\n", s);
  printf("密文:%s\n", s1);
  return 0;
}