CODEWITHSUNDEEP
pythonpython-3.xmath
Aayush peace
Aayush peace

Reputation: 55

Code not working for odd number at tens and hundreds's place

question is:

Write a program, which will find all such numbers between m and n (both included) such that each digit of the number is an even number.

Input Format:
The first line contains value m and n separated by a comma.

Output Format:
The numbers obtained should be printed in a comma-separated sequence on a single line.

Constraints:

  • 1000<=m<=9000
  • 1000<=n<=9000

However my code only works when no odd number is present at hundreds and thousands place. Where am I going wrong? Test cases and expected results:

Test Case 1

Test Case 2

Test Case 3

Test case 3 is failing in my case. Why is it so?

num=list(map(int,input().split(",")))
length=len(num)
list=[]
first=num[0]
last=num[length-1]
for i in range(first,last+1):
    count=0
    num1 = i
    k=i
    for j in range(4):
        last_digit=k%10
        k=i//10
        if(last_digit%2==0):
            count=count+1
    if(count==4):
        list.append(num1)
length2=len(list)
for i in range(length2):
    if(i<length2-1):
        print(list[i],end=',')
    else:
        print(list[i])

Upvotes: 2

Views: 274

Answers (2)

Martijn Pieters
Martijn Pieters

Reputation: 1122102

Your error lies here:

k=i
for j in range(4):
    last_digit=k%10
    k=i//10

You are assigning i // 10 to k each iteration, and i never changes, so you always only look at the last two digits, never anything else. If i starts at 1234, then k starts at 1234, last_digit becomes 4 and k becomes 123. From there on out, you only look at 123 (last_digit will be 3 and k = i // 10 so 123 again, each iteration).

You need to divide k:

k=i
for j in range(4):
    last_digit=k%10
    k=k//10

A simpler method would be to compare the digits (string values) to the set of even digits:

even = set('02468')

results = []
for i in range(first, last + 1):
    if set(str(i)) <= even:  # only even digits used
        results.append(i)

Upvotes: 1

Bram Vanroy
Bram Vanroy

Reputation: 28447

For readability's sake, I'd write something like so:

nums = list(map(int, input().split(",")))
all_even = []

for num in range(nums[0], nums[1]+1):
  # Skips the num if it's not even
  if num % 2 != 0:
    continue

  # Skips the num if any of its digits is not even
  # Note that it'll skip on the first item that is not even
  # so it is rather efficient as it does not necessarily 
  # need to iterate over *all* digits
  if any(int(digit) % 2 != 0 for digit in str(num)):
    continue

  # Appends the num to the final list
  all_even.append(str(num))

print(','.join(all_even))

Upvotes: 0

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