#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pii> vii;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef vector<vii> vvii;
#define fastIO ios::sync_with_stdio(false), cin.tie(NULL)
#define forw(i, l, r) for( int i = (l) ; i < (r) ; i++ )
#define forb(i, r, l) for( int i = (r) ; i >= (l) ; i-- )
#define log2i(x) (64 - __builtin_clzll(1ll * (x)) - 1)
#define numBit(x) (__builtin_popcountll(1ll * (x)))
#define getBit(x, i) ((x) >> (i) & 1)
#define Pi acos(-1.0l)
#define sz(x) int(x.size())
#define mt make_tuple
#define mp make_pair
#define fi first
#define se second
#define pb push_back
#define pf push_front
#define pob pop_back
#define pof pop_front
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define debug(x) cerr << #x << " = " << x << '\n';
const int N = 1e7 + 1;
int a, b;
ll ans = 0;
int sum[N];
bool kt[N];
vi primes;
int main() {
fastIO;
#ifndef ONLINE_JUDGE
//freopen("test.inp","r",stdin);
//freopen("test.out","w",stdout);
#endif
cin >> a >> b;
sum[1] = 1;
forw(i, 2, b + 1) {
if(!kt[i]) primes.emplace_back(i);
for(int j = 0; j < sz(primes) && primes[j] * i <= b; j++) {
kt[primes[j] * i] = true;
if(i % primes[j] == 0) break;
}
sum[i] = 1;
}
for(auto x:primes) {
for(ll i = x; i <= b; i *= x) {
for(ll j = i; j <= b; j += i) {
sum[j] = 1ll * sum[j] * (i * x - 1) / (i - 1);
}
}
}
forw(i, a, b + 1) ans += abs(sum[i] - 2 * i);
cout << ans;
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
204 KB |
Output is correct |
| 2 |
Correct |
1 ms |
332 KB |
Output is correct |
| 3 |
Correct |
4 ms |
844 KB |
Output is correct |
| 4 |
Correct |
478 ms |
51872 KB |
Output is correct |
| 5 |
Correct |
507 ms |
51860 KB |
Output is correct |
| 6 |
Correct |
500 ms |
51928 KB |
Output is correct |
| 7 |
Correct |
459 ms |
48008 KB |
Output is correct |
| 8 |
Correct |
109 ms |
13504 KB |
Output is correct |
