恺撒密码-题解(C语言代码)

#include<stdio.h>
#include<string.h>
char br[]={'V','W','X','Y','Z','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U' };//对应的明文字符
void conv(char *arr)
{
    int i;
    for(i=0;*(arr+i)!='\0';i++)
    {
        if(*(arr+i)>='A'&&*(arr+i)<='Z')
        {
            arr[i]=br[arr[i]-65];//对每个密文字符进行对应明文的转化
        }
        else continue;
    }
}
void main()
{
    char *p="ENDOFINPUT",*s="START",*e="END",ch[20],arr[200];
    while(gets(ch))
    {
        if(strcmp(ch,s)==0)
        {
            gets(arr);
            conv(arr);
            puts(arr);
        }
        else if(strcmp(ch,e)==0) continue;
        else if(strcmp(ch,p)==0) break;
    }
}