build pyramid one loop construction

main.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
char * char_repeat( int n, char c ) {
  char * dest = malloc(n+2);
  memset(dest, c, n);
  dest[n] = '\n';
  dest[n + 1] = '\0';
  return dest;
}
int main()

{
  int i, j, rows;
  char character = '*';
  
  printf("Enter number of rows: ");

  scanf("%d",&rows);
  char arr[rows * 2 -1][rows + 2]; 
  for(i = 0; i < rows; ++i)
  {
    strcpy(arr[i], char_repeat(rows - i, character));
    strcpy(arr[i+rows], char_repeat(i + 1, character));
  }
  for (j=0; j < rows * 2; j++) {
    printf("%s", arr[j]);
  }
  return 0;
}