1006 Do the Untwist

考察编程基础知识，用到字符和数字相互转化等。形式是描述清楚明文和暗文的转化规则。

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

 #define MAXLEN 71

 int length;

 void toCode(int code[],char text[]){
     int i;
     ;i<length;i++){
         if(text[i] == '_')
             code[i] = ;
         else if(text[i] == '.')
                 code[i] = ;
             else
                 code[i] = text[i] - ;
     }
 }

 void toText(char text[],int code[]){
     int i;
     ;i<length;i++){
         )
             text[i] = '_';
         )
                 text[i] = '.';
             else
                 text[i] = code[i] + ;
     }
     text[i] = ;
 }

 int inRange(int n){
     &&n<=)
         ;
     ;
 }

 void untwist(char textC[],int k){
     int i,j;
     int codeC[MAXLEN],codeP[MAXLEN];
     char textP[MAXLEN];

     toCode(codeC,textC);
     ;i<length;i++){
         j = (k*i)%length;
         if(inRange(codeC[i] + i))
             codeP[j] = codeC[i] + i;
         ))
                 codeP[j] = codeC[i] + i - ;
             ))
                     codeP[j] = codeC[i] + i - ;
                 ))
                         codeP[j] = codeC[i] + i - ;
     }
     toText(textP,codeP);
     printf("%s\n",textP);
 }

 int main(){
     int k;
     char textC[MAXLEN];
     while(scanf("%d",&k)&&k){
         scanf("%s",textC);
         length = strlen(textC);
         untwist(textC,k);
     }
     ;
 }