Codechef Problem: Counting Pretty Numbers Difficulty Rating:873

 

Problem

Vasya likes the number $239$. Therefore, he considers a number pretty if its last digit is $2$, $3$ or $9$.

Vasya wants to watch the numbers between $�$ and $�$ (both inclusive), so he asked you to determine how many pretty numbers are in this range. Can you help him?

Input

• The first line of the input contains a single integer $�$ denoting the number of test cases. The description of $�$ test cases follows.
• The first and only line of each test case contains two space-separated integers $�$ and $�$.

Output

For each test case, print a single line containing one integer — the number of pretty numbers between $�$ and $�$.

Solution:

# cook your dish here

def is_pretty(number):

    last_digit = number % 10

    return last_digit == 2 or last_digit == 3 or last_digit == 9

def count_pretty_numbers_in_range(L, R):

    count = 0

    for number in range(L, R + 1):

        if is_pretty(number):

            count += 1

    return count

T=int(input())

li=[]

for _ in range(T):

    L,R=map(int,input().split())

    pretty_count=count_pretty_numbers_in_range(L,R)

    print(pretty_count)