Submission #86327

#	Time	Username	Problem	Language	Result	Execution time	Memory
86327		dimash241	Savrsen (COCI17_savrsen)	C++14	60 / 120	49 ms	16500 KiB

savrsen

# include <stdio.h>
# include <bits/stdc++.h>


#define _USE_MATH_DEFINES_
#define ll long long
#define ld long double
#define Accepted 0
#define pb push_back
#define mp make_pair
#define sz(x) (int)(x.size())
#define every(x) x.begin(),x.end()
#define F first
#define S second
#define For(i,x,y)  for (ll i = x; i <= y; i ++) 
#define FOr(i,x,y)  for (ll i = x; i >= y; i --)
#define SpeedForce ios_base::sync_with_stdio(0), cin.tie(0)
// ROAD to...                                                                                                                                                                                                                Red

using namespace std;

inline bool isvowel (char c) {
	c = tolower(c);
    if (c == 'a' || c == 'e' || c == 'i' || c == 'y' || c == 'o' || c == 'u') return 1;
    return 0;
}

const double eps = 0.000001;
const ld pi = acos(-1);
const int maxn = 1e7 + 9;
const int mod = 1e9 + 7;
const ll MOD = 1e18 + 9;
const ll INF = 1e18 + 123;
const int inf = 2e9 + 11;
const int mxn = 1e6 + 9;
const int N = 6e5 + 123;                                          
const int M = 22;
const int pri = 997;
const int Magic = 2101;

const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, -1, 0, 1};
 
ll f[mxn];

ll sum (ll x) {
	ll res = 0;
	if (x == 1) return 0;
	for (int i = 1; i * (ll) i <= x; i ++) {
		if (x % i == 0) {
			res += i;
			if (x / i != i && x / i != x) res += x / i; 
		}
	}
	return res;
}

int main () {               
	int a, b;
	cin >> a >> b;
	if ((b - a + 1) * sqrt(b) <= 1e7) {
		ll ans = 0;
		for (int i = a; i <= b; i ++) {
			ans += abs(i - sum(i));
		}

		cout << ans;
		return 0;
	}
	for (int i = 1; i <= b; i ++) {
		for (int j = i + i; j <= b; j += i)
			f[j] += i; 
	}
	for (int i = 1; i <= b; i ++)
		f[i] = f[i - 1] + abs(i - f[i]);
   cout << f[b] - f[a - 1];
    return Accepted;
}

// Coded By OB

• Subtask 1: 60 / 120