oj.uz

답안 #474754

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
474754 2021-09-19T15:29:55 Z egod1537 팔찌 (kriii4_V) C++14
6 / 100
 1000 ms 31840 KB 
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")

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

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) {
	unordered_map<ll, ll> mp;
	while (num > 1)
		mp[low[num]]++, num /= low[num];
	vector<pi> ans;
	for (auto& p : mp) ans.push_back(p);
	return ans;
}
ll dfs(int num, ll n, ll k, ll now, vector<pi>& arr, vector<vector<ll>>& psum) {
	if (num == arr.size()) return phi[n/now] * pwk[now];
	ll ans = 0;
	for (int i = 0; i <= arr[num].cnt; i++)
		ans = (ans + dfs(num + 1, n, k, now * psum[num][i], arr, psum)) % mod;
	return ans;
}
ll r2;
ll func(ll n, ll k) {
	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, n, k, 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);

	phi[1] = 1;
	for (int i = 2; i <= 1000000; i++) {
		if (!vit[i]) 
			for (int j = i; j <= 1000000; j += i) {
				if (!low[j])low[j] = i;
				vit[j] = true;
			}
		phi[i] = i;
		for (int j = i; j != 1;) {
			ll p = low[j];
			while (j % p == 0) j /= p;
			phi[i] = (phi[i] * (p - 1)) / p;
		}
	}

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

	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 '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:41:10: 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]
   41 |  if (num == arr.size()) return phi[n/now] * pwk[now];
      |      ~~~~^~~~~~~~~~~~~
V.cpp: In function 'll func(ll, ll)':
V.cpp:52:20: 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]
   52 |  for (int i = 0; i < fact.size(); i++) {
      |                  ~~^~~~~~~~~~~~~

Subtask #1
6.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 153 ms 31616 KB Output is correct
2 Correct 148 ms 31688 KB Output is correct
3 Correct 149 ms 31636 KB Output is correct
4 Correct 148 ms 31672 KB Output is correct
5 Correct 146 ms 31636 KB Output is correct
6 Correct 144 ms 31684 KB Output is correct
7 Correct 144 ms 31724 KB Output is correct
8 Correct 149 ms 31680 KB Output is correct
9 Correct 149 ms 31632 KB Output is correct
10 Correct 142 ms 31684 KB Output is correct
11 Correct 143 ms 31684 KB Output is correct
12 Correct 154 ms 31740 KB Output is correct
13 Correct 146 ms 31684 KB Output is correct
14 Correct 156 ms 31696 KB Output is correct
15 Correct 146 ms 31704 KB Output is correct
16 Correct 147 ms 31684 KB Output is correct
17 Correct 145 ms 31668 KB Output is correct
18 Correct 150 ms 31748 KB Output is correct
19 Correct 155 ms 31684 KB Output is correct
20 Correct 148 ms 31704 KB Output is correct

Subtask #2
0 / 94.0

# 결과 실행 시간 메모리 Grader output
1 Correct 143 ms 31684 KB Output is correct
2 Correct 152 ms 31800 KB Output is correct
3 Correct 144 ms 31632 KB Output is correct
4 Correct 194 ms 31740 KB Output is correct
5 Correct 725 ms 31840 KB Output is correct
6 Correct 849 ms 31752 KB Output is correct
7 Correct 714 ms 31732 KB Output is correct
8 Correct 800 ms 31728 KB Output is correct
9 Correct 922 ms 31724 KB Output is correct
10 Execution timed out 1075 ms 31732 KB Time limit exceeded
11 Halted 0 ms 0 KB -