Codeforces Round 1004 (Div. 2) |
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Finished |
You are given a positive integer $$$n$$$. In one operation, you can add to $$$n$$$ any positive integer whose decimal representation contains only the digit $$$9$$$, possibly repeated several times.
What is the minimum number of operations needed to make the number $$$n$$$ contain at least one digit $$$7$$$ in its decimal representation?
For example, if $$$n = 80$$$, it is sufficient to perform one operation: you can add $$$99$$$ to $$$n$$$, after the operation $$$n = 179$$$, which contains the digit $$$7$$$.
Each test contains multiple test cases. The first line contains the number of test cases $$$t$$$ ($$$1 \le t \le 10^4$$$). The description of the test cases follows.
The only line of each test case contains an integer $$$n$$$ ($$$10 \leq n \leq 10^9$$$).
For each test case, output the minimum number of operations required for the number $$$n$$$ to contain the digit $$$7$$$.
16516061777123456891000000000200230019779898989868080000196701590
3 2 1 0 1 3 5 4 0 7 1 2 7 0 7 3
In the first test case, three operations are sufficient: $$$51 + 9 + 9 + 9 = 78$$$, which contains the digit $$$7$$$. It can be shown that it is impossible to achieve the goal in one or two operations.
In the second test case, two operations are sufficient: $$$60 + 9 + 9 = 78$$$.
In the third test case, one operation is sufficient: $$$61 + 9 = 70$$$.
In the fourth test case, $$$n$$$ already contains the digit $$$7$$$, so no operations are required.
In the fifth test case, you can add $$$99$$$ to $$$n$$$ to obtain a number containing the digit $$$7$$$.
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