CountDiv

CountDiv lesson 3 codility

class Solution {
    public int solution(int A, int B, int K) {
        // write your code in Java SE 8
        int first=0;
        int last=0;
        if(A%K==0){
            first=A/K;
        }else{
            first=(A-A%K+K)/K;            
        }
         if(B%K==0){
            last=B/K;
        }else{
            last=(B-B%K)/K;            
        }
        return last-first+1;
    }
}