CountDiv

tab1

Task Score     :100
Correctness   :100
Performance : 100

Task description

Codility Link

Write a function:

class Solution { public int solution(int A, int B, int K); }

that, given three integers A, B and K, returns the number of integers within the range [A..B] that are divisible by K, i.e.:

{ i : A ≤ i ≤ B, i mod K = 0 }

For example, for A = 6, B = 11 and K = 2, your function should return 3, because there are three numbers divisible by 2 within the range [6..11], namely 6, 8 and 10.

Write an efficient algorithm for the following assumptions:

• A and B are integers within the range [0..2,000,000,000];
• K is an integer within the range [1..2,000,000,000];
• A ≤ B.

Solution

public class CountDiv {

 public static void main(String[] args) {
  System.out.println(new CountDiv().solution(6, 11, 2));

 }
 
 public int solution(int A, int B, int K) {
  
  if(A>B) {
   return 0;
  }
  
  int count =0;
  
  B = B - (B%K);
  if(A<=B) {
   int diff = (B-A)/K;
    count = diff+1;
  }

 return count;
 }

}