oj.uz

Submission #474619

# Submission time Handle Problem Language Result Execution time Memory
474619 2021-09-19T08:08:57 Z egod1537 팔찌 (kriii4_V) C++14
6 / 100
 1000 ms 29760 KB 
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")

#include<bits/stdc++.h>

using namespace std;

typedef long long ll;
const ll mod = 1e9 + 7;

typedef pair<ll, ll> pi;
#define var first
#define cnt second

ll pwk[2000001], phi[1000001], low[1000001];
bitset<1000001> vit;
vector<ll> prime;

ll pow(ll x, ll p) {
	ll ret = 1, piv = x % mod;
	while (p) {
		if (p & 1) ret *= piv;
		piv *= piv;
		ret %= mod;
		piv %= mod;
		p >>= 1;
	}
	return ret;
}
ll revmod(ll x) { return pow(x, mod - 2) % mod; }	
vector<pi> getfactor(ll num) {
	vector<pi> ans;
	for (int i = 0; num > 1 && prime[i]*prime[i] <= num && i < prime.size(); i++) {
		ll now = prime[i];
		pi p = pi(now, 0);
		while (num % now == 0) {
			p.cnt++;
			num /= now;
		}
		if (p.cnt > 0) ans.push_back(p);
	}
	if (num > 1) ans.push_back(pi(num, 1));
	return ans;
}
ll dfs(int num, ll k, ll now, ll np, vector<pi>& arr, vector<vector<ll>>& psum) {
	if (num == arr.size()) return phi[np]*pwk[now];
	ll ans = 0;
	for (int i = 0; i <= arr[num].cnt; i++) 
		ans = (ans + dfs(num+1, k, now*psum[num][i], np*psum[num][arr[num].cnt-i], arr, psum))%mod;
	return ans;
}
ll r2;
ll func(ll n, ll k) {
	//if (n % 10000 == 0) cout << n << "\n";
	ll ans = 0;
	vector<pi> fact = getfactor(n);
	vector<vector<ll>> psum(fact.size());
	for (int i = 0; i < fact.size(); i++) {
		psum[i].resize(fact[i].cnt+1);
		psum[i][0] = 1;
		for (int j = 1; j <= fact[i].cnt; j++) 
			psum[i][j] = psum[i][j - 1] * fact[i].var;
	}
	ans = dfs(0, k, 1, 1, fact, psum);
	if (n % 2) ans = (ans + (n * pwk[n/2+1])%mod)%mod;
	else {
		ll pw = (pwk[n/2] + pwk[n/2+1]) % mod;
		ans = (ans + (((n * pw)%mod)*r2)%mod)%mod;
	}

	return (ans * revmod(2 * n)) % mod;
}

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0), cout.tie(0);

	for (int i = 2; i <= 1000000; i++) {
		if (!vit[i]) prime.push_back(i);
		else continue;
		for (int j = 2 * i; j <= 1000000; j += i) vit[j] = true;
	}

	ll n, k; cin >> n >> k;

	phi[1] = 1;
	for (int i = 2; i <= n; i++) {
		for (int j = i; j <= n; j += i) {
			if (!low[j]) low[j] = i;
		}
		phi[i] = i;
		for (int j = i; j != 1; ) {
			int p = low[j];
			while (j % p == 0) {
				j /= p;
			}
			phi[i] = (1ll * phi[i] * (p - 1)) / p;
		}
	}

	pwk[0] = 1;
	for (int i = 1; i <= 2000000; i++) pwk[i] = (pwk[i - 1] * k) % mod;
	r2 = revmod(2);

	ll ans = 1;
	for (int i = 1; i <= n; i++) ans = (ans + func(i, k)) % mod;
	cout << ans;

	return 0;
}

Compilation message

V.cpp: In function 'std::vector<std::pair<long long int, long long int> > getfactor(ll)':
V.cpp:34:59: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |  for (int i = 0; num > 1 && prime[i]*prime[i] <= num && i < prime.size(); i++) {
      |                                                         ~~^~~~~~~~~~~~~~
V.cpp: In function 'll dfs(int, ll, ll, ll, std::vector<std::pair<long long int, long long int> >&, std::vector<std::vector<long long int> >&)':
V.cpp:47:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |  if (num == arr.size()) return phi[np]*pwk[now];
      |      ~~~~^~~~~~~~~~~~~
V.cpp: In function 'll func(ll, ll)':
V.cpp:59:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   59 |  for (int i = 0; i < fact.size(); i++) {
      |                  ~~^~~~~~~~~~~~~

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 25 ms 16840 KB Output is correct
2 Correct 25 ms 16800 KB Output is correct
3 Correct 25 ms 16820 KB Output is correct
4 Correct 27 ms 16764 KB Output is correct
5 Correct 27 ms 16840 KB Output is correct
6 Correct 25 ms 16788 KB Output is correct
7 Correct 25 ms 16804 KB Output is correct
8 Correct 24 ms 16804 KB Output is correct
9 Correct 24 ms 16828 KB Output is correct
10 Correct 24 ms 16772 KB Output is correct
11 Correct 24 ms 16816 KB Output is correct
12 Correct 24 ms 16760 KB Output is correct
13 Correct 24 ms 16760 KB Output is correct
14 Correct 24 ms 16804 KB Output is correct
15 Correct 24 ms 16840 KB Output is correct
16 Correct 26 ms 16796 KB Output is correct
17 Correct 24 ms 16776 KB Output is correct
18 Correct 24 ms 16840 KB Output is correct
19 Correct 25 ms 16748 KB Output is correct
20 Correct 25 ms 16788 KB Output is correct

Subtask #2
0 / 94.0

# Verdict Execution time Memory Grader output
1 Correct 24 ms 16840 KB Output is correct
2 Correct 24 ms 16840 KB Output is correct
3 Correct 25 ms 16872 KB Output is correct
4 Correct 76 ms 17612 KB Output is correct
5 Correct 741 ms 26432 KB Output is correct
6 Correct 929 ms 28608 KB Output is correct
7 Correct 690 ms 25916 KB Output is correct
8 Correct 900 ms 28092 KB Output is correct
9 Execution timed out 1012 ms 29760 KB Time limit exceeded
10 Halted 0 ms 0 KB -