Problem with RC4 encryption

void prepareKey (char key[], int *s)
{
     int t[4], i, j, temp;
     cout<<"S[]= ";
     for(i=0;i<4;i++)//assigning S[]
     {
          s[i]=i;
          t[i]=key[i%strlen(key)];          
     }         
                
     for(i=0;i<4;i++) //swapping of S[]
     {
          j=(j+s[i]+t[i])%4;
          temp=s[i];
          s[i]=s[j];
          s[j]=temp;
     }
}

void rc4 (char plainText[], int s[], char *key, char *ciphertext)
{
     int m, n, i, q;
     
     for(i=0;i<16;i++)
         ciphertext[i]=0;
     cout<<"Cipher Text:";  
     for(i=0;i<strlen(plainText);i++)
     {
          int temp, temp2;
          m=(m+1)% 4;
          n=(n+s[m])% 4;
          temp=s[m];
          s[m]=s[n];
          s[n]=temp;
          q=(s[m]+s[n])%4;
          temp2 = s[q];

          ciphertext[i]=plainText[i]^temp2;
          
           cout.fill('0');
          cout.width(8);
          cout << right <<convBase(ciphertext[i],2)<<" ";                    
                    
      }
      cout<<endl;
}

int main()
{         
         for(i=0;i<4;i++)//assigning S[]
         {
              S[i]=i;
              SD[i]=i;        
          }
}

void prepareKey (char key[], int *s)
{
     int g=0, i, j=0, temp=0;  
                               
     for(i=0;i<4;i++) //swapping of S[]
     {
          j=(j+s[i]+key[i%strlen(key)])%4;
          temp=s[i];
          s[i]=s[j];
          s[j]=temp;
     }
}

void rc4 (char plainText[], int s[], char *key, char *ciphertext)
{
     int m=0, n=0, i, q=0;
     
     for(i=0;i<16;i++)
         ciphertext[i]=0;
     cout<<"Cipher Text:";  
     for(i=0;i<strlen(plainText);i++)
     {
          int temp, temp2;
          m=(m+1)% 4;
          n=(n+s[m])% 4;
          temp=s[m];
          s[m]=s[n];
          s[n]=temp;
          q=(s[m]+s[n])%4;
          temp2 = s[q];

          ciphertext[i]=plainText[i]^temp2;
          
          cout.fill('0');
          cout.width(8);
          cout << right <<convBase(ciphertext[i],2)<<" ";                               
      }
      cout<<endl;
}