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++ (Clang 10.0.0) (judge verdict: Accepted)

#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<vector>
#include<string>
#include<iostream>
using namespace std;
#define N 100010
long long int gcd(long long a, long long b) {
    return a%b==0?b:gcd(b,a%b);
}
int main(){
    int n,s;
    int t,l,r,d;
    while (scanf("%d %d %d",&l,&r,&d)!=EOF) {
        int ans = 0;
        for (int i=l;i<=r;i++) {
            if (i%d==0)
                ans++;
        }
        cout << ans << endl;

    }

    return 0;
}
/*
5
1 2 3 4 5
4
1 1 1 1
1 1 1 2
1 2 5 1
1 3 5 2
*/