Columnar in C

/* Program to implement Columnar Cipher */

#include<stdio.h>

#include<string.h>

void main()

{

char k[20]={'\0'},pt[30]={'\0'},key[30]={'\0'},mat[10][10]={'\0'},ct[30]={'\0'};

int i=0,j=0,no[10]={0},ctr,z,c=0,a=0;

//clrscr();

printf("Enter the plaintext:\n");

gets(pt);

printf("Enter the key:\n");

gets(k);

strcpy(key,k);

strcat(k,pt);

strcpy(pt,k);

printf("Enter the ordering starting from 0 to the (keylength-1):\n");

for(i=0;i

{

scanf("%d",&no[i]);

}

j=0;

ctr=j;

printf("The matrix is:\n");

for(i=0;i

{

for(j=j;ctr

{

if(pt[j]!='\0')

{

mat[i][ctr]=pt[j];

printf("%c",mat[i][ctr]);

ctr++;

}

else

{

goto out;

}

}

ctr=0;

if(i==0) printf("\n");

printf("\n");

}

out:

printf("\n\nThe Encrypted text is:\n");

for(i=0;i

{

for(j=0;j

{

if(no[i]==j)

{

for(z=1;z<10;z++)

{

if(isalpha(mat[z][j]))

{

printf("%c",mat[z][j]);

ct[a]=mat[z][j];

a++;

}

}

}

}

}

printf("\n\nDecrypted Ciphertext is:\n");

for(a=0;a<30;a++)

{

if(isalpha(ct[a]) || isspace(ct[a]))

c++;

}

for(i=1;i

{

for(j=0;j

{

if(isalpha(mat[i][j]))

printf("%c",mat[i][j]);

else

break;

}

}

// getch();

}

/* Output */

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