A13657 | $Sum of Digits$

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内存限制256MB

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题目描述

Let $f(x)$ be the sum of digits of a decimal number $x$ . Find the smallest non-negative integer $x$ such that $f(x) + f(x + 1) + \dots + f(x + k) = n$ .

The first line contains one integer $t$ ( $1 \le t \le 150$ ) — the number of test cases. Each test case consists of one line containing two integers $n$ and $k$ ( $1 \le n \le 150$ , $0 \le k \le 9$ ).

For each test case, print one integer without leading zeroes. If there is no such $x$ that $f(x) + f(x + 1) + \dots + f(x + k) = n$ , print $-1$ ; otherwise, print the minimum $x$ meeting that constraint.

输入 #1

输出 #1

1
0
4
-1
599998
99999999999
7997

C++ 编辑器

输入

输出