Problem:
Score : 200 points

Problem Statement

You are given nonnegative integers a and b (a ≤ b), and a positive integer x.
Among the integers between a and b, inclusive, how many are divisible by x?

Constraints

0 ≤ a ≤ b ≤ 10^{18}

1 ≤ x ≤ 10^{18}

Input

The input is given from Standard Input in the following format:

a b x

Output

Print the number of the integers between a and b, inclusive, that are divisible by x.

Sample Input 1

4 8 2

Sample Output 1

3

There are three integers between 4 and 8, inclusive, that are divisible by 2: 4, 6 and 8.

Sample Input 2

0 5 1

Sample Output 2

6

There are six integers between 0 and 5, inclusive, that are divisible by 1: 0, 1, 2, 3, 4 and 5.

Sample Input 3

9 9 2

Sample Output 3

0

There are no integer between 9 and 9, inclusive, that is divisible by 2.

Sample Input 4

1 1000000000000000000 3

Sample Output 4

333333333333333333

Watch out for integer overflows.

Solution in Java (OpenJDK 1.8.0) (judge verdict: Runtime Error)


import java.util.*;

public class Main
 {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int a, b, c;
        int count = 0;
        a = input.nextInt();
        b = input.nextInt();
        c = input.nextInt();
        for (int i = a; b >= i; i++) {

            int s = i % c;
            if (s == 0) {
                count++;
            }
        }
        System.out.println(count);
        if (count == 3) {
            System.out.printf("There are three integers between %d and %d, inclusive, that are divisible by %d: %d, 6 and %d.\n", a, b, c, a, b);
        }
        else
            if (count == 6) {
            System.out.println("There are six integers between 0 and 5, inclusive, that are divisible by 1:0,1,2,3,4 and 5.");
        }
       else
                if (count == 0) {
            System.out.println("There are no integer between9and9, inclusive, that is divisible by2");
        } else {
            System.out.println("Watch out for integer overflows.");
        }
    }
}