sdnuoj 1023. Smart cashier

Calculating the minimum amount of money to find is adding and subtracting

#include <cstdio>
#include <cstring>
#include <string>
#include <cmath>
#include <iostream>
#include <algorithm>
#include <vector>
#include <stack>
#include <queue>
#include <stdlib.h>
#include <sstream>
#include <map>
#include <set>
typedef long long ll;
using namespace std;
int ar[10005];
int main()
{
    
    
    int n, m, sum, c, d, a, b, e;
    int k;
    a = 0;
    b = 0;
    c = 0;
    d = 0;
    e = 0;
    cin>>n;
    k = n;
    a = n/100;
    b = (n - a*100)/50;
    c = (n - a*100 - b*50)/10;
    d = (n - a*100 - b*50 - 10*c)/5;
    e = n - 100*a - 50*b - 10*c - 5*d;
    cout<<a+b+c+d+e;
    return 0;
}