2 shunfurh shunfurh 于 2017.01.15 21:26 提问

The Lucky Numbers

Description

John and Brus are freshmen at the primary school. Their first home task is to learn some integer numbers. It is not so hard for the guys and they decide to impress their teacher by learning all lucky numbers between A and B, inclusive.
As you already know from the previous year contest 4 and 7 are lucky digits, and all the other digits are not lucky. A lucky number is a number that contains only lucky digits in decimal notation.
After learning all lucky numbers in [A, B] range John and Brus still have some free time and now they decide to learn additionally each lucky number N that is out of [A, B] range, but the reversed number of N is in this range. Here reversed number of N is the number N written in decimal notation, but the order of digits is reversed. For example, the reversed number of 447 is 744 and reversed number of 774474444 is 444474477.
You are given integers A and B and your task is to find the total number of lucky numbers learned by John and Brus.
Input

The first line contains single integer T – the number of test cases. Each test case consists of a single line containing two integers A and B separated by a single space.
Output

For each test case print a single line containing the total number of lucky numbers learned by John and Brus.
Sample Input

2
1 100
44 47
Sample Output

6
3

2个回答

caozhy
caozhy   Ds   Rxr 2017.01.22 23:48
已采纳
dabocaiqq
dabocaiqq   2017.01.21 22:54
Csdn user default icon
上传中...
上传图片
插入图片
准确详细的回答,更有利于被提问者采纳,从而获得C币。复制、灌水、广告等回答会被删除,是时候展现真正的技术了!