Playfair Key Matrix Generation: Keyword validation according to the specification given in the algorithm.

/*Playfair Key Matrix Generation: Keyword validation according to the specification given in the algorithm.*/

#include<stdio.h>

int main(){

  char key[10];
  int i,j,flag=0, cnt=0, key_check[26]={};

  printf("Enter your keyword:");
  scanf("%s",key);

  //Logic to count character frequency in MONARCHY
  for(i=0; i<strlen(key); i++)
  {
key_check[key[i]%65]++;
  }

  for(i=0; i<26; i++)
  {
if(key_check[i] > 1)
flag=1;
//Logic to display frequency
//printf("%c=%d \n",i+65, key_check[i]);
  }

  if(flag==1)
printf("Keyword %s is not suitable for generating Playfair Key Matrix.", key);
  else
printf("Keyword %s is ok for generating Playfair Key Matrix.", key);

  return 0;
}

//This program will check only keywords enter in Capital letters.

Output - 1
Enter your keyword:MONARCHY
Keyword MONARCHY is ok for generating Playfair Key Matrix.

Output - 2
Enter your keyword:HELLO
Keyword HELLO is not suitable for generating Playfair Key Matrix.