Closest Number

Easy

0/40

Average time to solve is 15m

1 upvote

Asked in companies

Problem statement

You are given two integers N and M. Can you find a number closest to N and divisible by M.

Here closest number to N means a number whose absolute difference is minimum with N. If there are two integers closest to N then the answer will be the one which is a smaller integer.

For Example:

Let N = 8 and M = 3
The numbers divisible by 3 are 3, 6, 9, …
From these numbers 9 is closest to 8. Thus, the answer is 9.

Detailed explanation ( Input/output format, Notes, Images )

Input format:

The first line of input contains an integer ‘T’ denoting the number of test cases.

The first and only line of each test case contains two integers N and M.

Output format :

For each test case, return an integer closest to N and divisible by M.

Note:

You do not need to print anything, it has already been taken care of. Just implement the given function.

Constraints:

1 <= T <= 10^5
-10^9 <= N <= 10^9
1 <= M <= 10^9

Time limit: 1 sec

Sample Input 1:

2
8 3
-15 6

Sample Output 1:

9
-18

Explanation

Test Case 1:
Refer to the example described above.

Test Case 2:
The closest number to -15 which is divisible by 6 are -12 and -18 as the absolute difference of both by -15 is equal to 3. So, the answer will be -18 as it is smaller than -12.

Sample Input 2:

Sample Output 2:

12
12
16

Hint 1

Hint 2

The brute force approach is to loop over the number closest to N and find the one which is divisible by M.

Approaches (2)

Approach 1

Approach 2

Brute Force

The brute force approach is to loop over the number closest to N and find the one which is divisible by M.

Run a loop from 0 to M-1:
- Check if N - i is divisible by M, if yes return N - i
- Check if N + i is divisible by M, if yes return N + i

Time Complexity

O(M) per test case where M is the dividing number.

In the worst case, we will be running a loop M times.

Space Complexity

O(1) per test case.

In the worst case, we are using constant extra space.

(100% EXP penalty)

Closest Number

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