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++ (GCC 9.2.1) (judge verdict: Accepted)

#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,n) for(int i=a;i<n;i++)
#define per(i,a,n) for(int i=n-1;i>=a;i--)
#define VI vector<int>
#define PII pair<int,int>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define ll long long
#define db double
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)x.size())
#define out(x) cout<<(#x)<<" = "<<x<<endl
mt19937 mrand(random_device{}());
const ll mod = 1000000007;
int rnd(int x){return mrand()%x;}
clock_t ac; double TLE(){return (double)(clock()-ac)/CLOCKS_PER_SEC;}

int main(){
 ios::sync_with_stdio(0);
 cin.tie(0);
 int d,l,r;
 cin>>l>>r>>d;
 if(l%d==0){
 	cout<<((r/d)-(l/d)+1);
 }
 else{
 	cout<<((r/d)-(l/d));
 }
}