C code to Encrypt & Decrypt Message using Transposition Cipher

C Program

#include<stdio.h> 
#include<string.h> 
void cipher(int i,int c);
int findMin();
void makeArray(int,int);
char arr[22][22],darr[22][22],emessage[111],retmessage[111],key[55];
char temp[55],temp2[55];
int k=0;
int main() {
 char *message,*dmessage;
 int i,j,klen,emlen,flag=0;
 int r,c,index,min,rows;
 clrscr();
 printf("Enetr the key\n");
 fflush(stdin);
 gets(key);
 printf("\nEnter message to be ciphered\n");
 fflush(stdin);
 gets(message);
 strcpy(temp,key);
 klen=strlen(key);
 k=0;
 for (i=0; ;i++) {
  if(flag==1) 
      break;
  for (j=0;key[j]!=NULL;j++) {
   if(message[k]==NULL) {
    flag=1;
    arr[i][j]='-';
   } else {
    arr[i][j]=message[k++];
   }
  }
 }
 r=i;
 c=j;
 for (i=0;i<r;i++) {
  for (j=0;j<c;j++) {
   printf("%c ",arr[i][j]);
  }
  printf("\n");
 }
 k=0;
 for (i=0;i<klen;i++) {
  index=findMin();
  cipher(index,r);
 }
 emessage[k]='\0';
 printf("\nEncrypted message is\n");
 for (i=0;emessage[i]!=NULL;i++) 
    printf("%c",emessage[i]);
 printf("\n\n");
 //deciphering 
 emlen=strlen(emessage);
 //emlen is length of encrypted message 
 strcpy(temp,key);
 rows=emlen/klen;
 //rows is no of row of the array to made from ciphered message 
 rows;
 j=0;
 for (i=0,k=1;emessage[i]!=NULL;i++,k++) {
  //printf("\nEmlen=%d",emlen); 
  temp2[j++]=emessage[i];
  if((k%rows)==0) {
   temp2[j]='\0';
   index=findMin();
   makeArray(index,rows);
   j=0;
  }
 }
 printf("\nArray Retrieved is\n");
 k=0;
 for (i=0;i<r;i++) {
  for (j=0;j<c;j++) {
   printf("%c ",darr[i][j]);
   //retrieving message 
   retmessage[k++]=darr[i][j];
  }
  printf("\n");
 }
 retmessage[k]='\0';
 printf("\nMessage retrieved is\n");
 for (i=0;retmessage[i]!=NULL;i++) 
      printf("%c",retmessage[i]);
 getch();
 return(0);
}
void cipher(int i,int r) {
 int j;
 for (j=0;j<r;j++) { {
   emessage[k++]=arr[j][i];
  }
 }
 // emessage[k]='\0';
}
void makeArray(int col,int row) {
 int i,j;
 for (i=0;i<row;i++) {
  darr[i][col]=temp2[i];
 }
}
int findMin() {
 int i,j,min,index;
 min=temp[0];
 index=0;
 for (j=0;temp[j]!=NULL;j++) {
  if(temp[j]<min) {
   min=temp[j];
   index=j;
  }
 }
 temp[index]=123;
 return(index);
}