ABCDPattern

#include <stdio.h>

int main(){

    char letters[]="ABCDEFGHIJKLMNOPQRSTUVWXYZ";                                                                                                                                   

    /*
    A

    BB

    CCC

    DDDD

    EEEEE

    */

   int n;

   printf("Enter the size: ");                                                                                                                     

   scanf("%d",&n);

   for(int i=0;i<n;i++){

    for(int j=0;j<=i;j++){

        printf("%c ",letters[i]);

    }

    printf("\n");

   }

    return 0;

}

Output