oj.uz

답안 #474577

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
474577 2021-09-19T07:11:28 Z egod1537 팔찌 (kriii4_V) C++14
6 / 100
 1000 ms 16076 KB 
#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];

ll pow(ll x, ll cnt) {
	if (cnt == 0) return 1;
	ll mid = pow(x, cnt >> 1)%mod;
	return (((mid * mid)%mod) * (cnt % 2 ? x : 1)) % mod;
}
ll revmod(ll x) { return pow(x, mod - 2) % mod; }	
vector<pi> getfactor(ll num) {
	vector<pi> ans;
	for (ll i = 2; i * i <= num; i++) {
		pi p = pi(i, 0);
		while (num % i == 0) {
			p.cnt++;
			num /= i;
		}
		if (p.cnt > 0) ans.push_back(p);
	}
	if (num > 1) ans.push_back(pi(num, 1));
	return ans;
}
ll eulerp(vector<pi>& factor, vector<vector<ll>>& psum) {
	//return 1;
	ll ans = 1;
	for (int i = 0; i < factor.size(); i++) {
		pi& p = factor[i];
		if (p.cnt == 0) continue;
		ans = (ans * ((psum[i][p.cnt-1] * (p.var - 1)) % mod)) % mod;
	}
	return ans;
}
ll dfs(int num, ll k, ll now, vector<pi>& arr, vector<pi>& dq, vector<vector<ll>>& psum) {
	if (num == arr.size()) return eulerp(dq, psum)*pwk[now];
	ll ans = 0;
	for (int i = 0; i <= arr[num].cnt; i++) {
		dq[num].cnt = arr[num].cnt - i;
		ans = (ans + dfs(num+1, k, now*psum[num][i], arr, dq, 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;
	}
	vector<pi> dq(fact.begin(), fact.end());
	ans = dfs(0, k, 1, fact, dq, 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);

	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 eulerp(std::vector<std::pair<long long int, long long int> >&, std::vector<std::vector<long long int> >&)':
V.cpp:36:20: 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]
   36 |  for (int i = 0; i < factor.size(); i++) {
      |                  ~~^~~~~~~~~~~~~~~
V.cpp: In function 'll dfs(int, ll, ll, std::vector<std::pair<long long int, long long int> >&, std::vector<std::pair<long long int, long long int> >&, std::vector<std::vector<long long int> >&)':
V.cpp:44:10: 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]
   44 |  if (num == arr.size()) return eulerp(dq, psum)*pwk[now];
      |      ~~~~^~~~~~~~~~~~~
V.cpp: In function 'll func(ll, ll)':
V.cpp:58:20: 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]
   58 |  for (int i = 0; i < fact.size(); i++) {
      |                  ~~^~~~~~~~~~~~~

Subtask #1
6.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 17 ms 15964 KB Output is correct
2 Correct 18 ms 15948 KB Output is correct
3 Correct 17 ms 15876 KB Output is correct
4 Correct 17 ms 15864 KB Output is correct
5 Correct 17 ms 15916 KB Output is correct
6 Correct 17 ms 15924 KB Output is correct
7 Correct 17 ms 15884 KB Output is correct
8 Correct 18 ms 15948 KB Output is correct
9 Correct 17 ms 15948 KB Output is correct
10 Correct 18 ms 15944 KB Output is correct
11 Correct 17 ms 15952 KB Output is correct
12 Correct 17 ms 15952 KB Output is correct
13 Correct 18 ms 15908 KB Output is correct
14 Correct 18 ms 15872 KB Output is correct
15 Correct 17 ms 15948 KB Output is correct
16 Correct 17 ms 15936 KB Output is correct
17 Correct 17 ms 15948 KB Output is correct
18 Correct 17 ms 15900 KB Output is correct
19 Correct 19 ms 15936 KB Output is correct
20 Correct 19 ms 15948 KB Output is correct

Subtask #2
0 / 94.0

# 결과 실행 시간 메모리 Grader output
1 Correct 18 ms 15932 KB Output is correct
2 Correct 17 ms 15948 KB Output is correct
3 Correct 18 ms 15924 KB Output is correct
4 Correct 90 ms 16076 KB Output is correct
5 Execution timed out 1094 ms 15948 KB Time limit exceeded
6 Halted 0 ms 0 KB -