What is following code doing? What would it print for input as 3?

n = int(input( "Enter an integer:" ))
if n < 1 :
  print ("invalid value")
else :
  for i in range(1, n + 1):
    print (i * i)

How are following two code fragments different from one another? Also, predict the output of the following code fragments :

(a)

n = int(input( "Enter an integer:" ))
if n > 0 :
    for a in range(1, n + n ) :
        print (a / (n/2))
    else :
        print ("Now quiting")

(b)

n = int(input("Enter an integer:"))
if n > 0 :
    for a in range(1, n + n) :
        print (a / (n/2))
else :
    print ("Now quiting")

Rewrite the following code fragment using for loop:

while num > 0 :
    print (num % 10)
    num = num/10

Rewrite the following code fragment using for loop:

while num > 0 :
    count += 1
    sum += num
        num –= 2
        if count == 10 :
            print (sum/float(count))
            break