Prata ch 6 exs 5

#include <stdio.h>
#include <stdlib.h>
//if user entered D, output should be as follows:
//A
//ABA
//ABCBA
//ABCDCBA

int main()
{
    char ch,tch;
    int i,j;
    scanf("%c",&ch);

    for(i=0;i<=ch-'A';i++) //number of strings
    {
        tch= 'A'-1;

        for(j=0;j<i+1;j++) //letters in ascending order
        {
            printf("%c",++tch);
        }

        for(j=0;j<i;j++) //letters in descending order
        {
            printf("%c",--tch);
        }

        printf("\n");

    }

    return 0;
}