MinAdd Codechef Solution

Problem

Chef loves problems about digits and he came up with an interesting one.

Chef has given you two integers $N$ and $K$. You should find the minimum non-negative integer $X$, such that $N+X$ has at most $K$ distinct digits in its decimal representation.

For example, $1231$ has three distinct digits and $100$ has two distinct digits.

Input Format

• The first line of input will contain a single integer $T$, denoting the number of test cases.
• The first and only line of each test case consists of two space-separated integers $N$ and $K$, as described in the problem statement.

Output Format

For each test case, output on a new line the minimum non-negative integer $X$ which satisfies the problem conditions.

Constraints

Sample 1:

9
30 1
56 4
364 2
125 3
37662730 3
41872528 4
73170084 8
90032975 1
7487471 3

3
0
2
0
603
1583
0
9967024
3

Explanation:

Test case $1$: $30$ has $2$ distinct digits which is more than $1$, so we should add $3$ to $30$ to make it equal to $33$ which has only $1$ distinct digit.