Problem:
Score : 100 points

Problem Statement

How many multiples of d are there among the integers between L and R (inclusive)?

Constraints

All values in input are integers.

1 \leq L \leq R \leq 100

1 \leq d \leq 100

Input

Input is given from Standard Input in the following format:

L R d

Output

Print the number of multiples of d among the integers between L and R (inclusive).

Sample Input 1

5 10 2

Sample Output 1

3

Among the integers between 5 and 10, there are three multiples of 2: 6, 8, and 10.

Sample Input 2

6 20 7

Sample Output 2

2

Among the integers between 6 and 20, there are two multiples of 7: 7 and 14.

Sample Input 3

1 100 1

Sample Output 3

100

Solution in C# (.NET Core 3.1.201) (judge verdict: Runtime Error)

using System;
using System.Linq;

class C
{
	static void Main()
	{
        int  N = int.Parse(Console.ReadLine());
        /*int[] a  = Console.ReadLine()
                            .Split(' ')
                            .Select(a => int.Parse(a))
                            .ToArray();*/
		
        for(int i = 1; i<=N; i++){
            int Count_a=0;
            int Count_b=0;
            int Count_c=0;
            double dMax = Math.Pow((double) i -2.0, 0.5) - 1.0;
            int iMax_c = (int)Math.Floor(dMax);
            int iMax_a = (int)Math.Floor(Math.Pow((double) i / 6.0, 0.5));
            int iMax_b = (int)Math.Floor(Math.Pow((double) i / 6.0, 0.5));

           /* 
            for(int x=1;x<=iMax_a;x++)
            {
                if(6*x*x == i)
                {
                    Count_a++;
                }
                else if(6*x*x > i)
                {
                    break;
                }

            }
            */

            if(Math.Pow((double) i / 6.0, 0.5) == 0.0) Count_a =1;

            for(int x=1;x<=iMax_c+1;x++)
            {
            for(int z=1;z<x;z++)
            {
                if(3*x*x +z*z+2*z*x== i)
                {
                    Count_b++;
                }
                else if(3*x*x +z*z+2*z*x > i)
                {
                    break;
                }
            }
            }
            


            for(int x=1;x<=iMax_c+1;x++)
            {
            for(int y=1;y<x;y++)
            {
            for(int z=1;z<y;z++)
            {
                if(x*x+y*y+z*z+x*y+y*z+z*x == i)
                {
                    Count_c++;
                }
                else if(x*x+y*y+z*z+x*y+y*z+z*x > i)
                {
                    break;

                }
            }
            }
            }

            Console.WriteLine((Count_a + Count_b * 3 +Count_c*6).ToString());
        }


        
        
	}
}