problem 30(iv)

#include <stdio.h>

int main ()
{
  int n;
  printf("Enter a value of n: ");
  scanf("%d", &n);

  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= i; j++) {
      printf("%d", i);
    }
    printf("\n");
  }

  return 0;
}

Enter a value for n: