답안 #19851

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
19851 2016-02-25T06:15:59 Z tonyjjw 팔찌 (kriii4_V) C++14
100 / 100
663 ms 54220 KB
//*
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <time.h>
#include <stdlib.h>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <numeric>
#include <functional>
#define MOD 1000000007
#define MAX 0x3f3f3f3f
#define MAX2 0x3f3f3f3f3f3f3f3fll
#define ERR 1e-10
#define mp make_pair
#define all(x) (x).begin(), (x).end()
#pragma warning(disable:4996)
using namespace std;

typedef long long ll;
typedef long double ldb;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<double, double> pdd;

int n, m;
ll pi[1040000];
ll powm[1040000];
int comp[1040000];
ll xans[1040000];
ll inv[2040000];
ll xsum[1040000];

ll mul_inv(ll a, ll b=MOD)
{
	ll b0=b, t, q;
	ll x0=0, x1=1;
	if(b == 1) return 1;
	while(a > 1)
	{
		q=a/b;
		t=b, b=a%b, a=t;
		t=x0, x0=x1-q*x0, x1=t;
	}
	if(x1 < 0) x1+=b0;
	return x1;
}


ll modpow(ll x, ll y)
{
	ll ans=1;
	while(y)
	{
		if(y%2) ans*=x, ans%=MOD;
		x*=x, x%=MOD, y/=2;
	}
	return ans;
}

int main()
{
	int i, j, k;
	cin>>n>>m;
	//int t=clock();
	for(i=1;i<=n;i++) pi[i]=i;
	powm[0]=1;
	for(i=1;i<=n;i++) powm[i]=powm[i-1]*m, powm[i]%=MOD;
	for(i=1;i<=n*2;i++) inv[i]=mul_inv(i);
	ll ans=0;
	for(i=1;i<=n;i++)
	{
		xsum[i]=powm[i]*inv[i]%MOD;
	}
	for(i=1;i<=n;i++) xsum[i]+=xsum[i-1], xsum[i]%=MOD;
	for(i=1;i<=n;i++)
	{
		ll u=0;
		int k=1;
		for(j=i;j<=n;j+=i)
		{
			if(j != i && i >= 2) comp[j]=1;
			if(i >= 2 && !comp[i])
			{
				pi[j]/=i, pi[j]*=i-1;
			}
			//u+=powm[k++]*inv[j*2]%MOD;
		}
		u+=xsum[n/i]*inv[2*i]%MOD;
		//u%=MOD;
		ans+=pi[i]*u%MOD;
	}
	ans%=MOD;
	for(i=1;i<=n;i++)
	{
		if(i%2 == 0)
		{
			ans+=inv[4]*(m+1)%MOD*powm[i/2]%MOD;
		}
		else
		{
			ans+=inv[2]*powm[(i+1)/2]%MOD;
		}
	}
	ans++;
	ans%=MOD;
	cout<<ans;
	return 0;
}
//*/
# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 54220 KB Output is correct
2 Correct 0 ms 54220 KB Output is correct
3 Correct 0 ms 54220 KB Output is correct
4 Correct 0 ms 54220 KB Output is correct
5 Correct 0 ms 54220 KB Output is correct
6 Correct 0 ms 54220 KB Output is correct
7 Correct 0 ms 54220 KB Output is correct
8 Correct 1 ms 54220 KB Output is correct
9 Correct 0 ms 54220 KB Output is correct
10 Correct 0 ms 54220 KB Output is correct
11 Correct 0 ms 54220 KB Output is correct
12 Correct 0 ms 54220 KB Output is correct
13 Correct 0 ms 54220 KB Output is correct
14 Correct 0 ms 54220 KB Output is correct
15 Correct 0 ms 54220 KB Output is correct
16 Correct 0 ms 54220 KB Output is correct
17 Correct 0 ms 54220 KB Output is correct
18 Correct 0 ms 54220 KB Output is correct
19 Correct 0 ms 54220 KB Output is correct
20 Correct 0 ms 54220 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 54220 KB Output is correct
2 Correct 0 ms 54220 KB Output is correct
3 Correct 2 ms 54220 KB Output is correct
4 Correct 31 ms 54220 KB Output is correct
5 Correct 394 ms 54220 KB Output is correct
6 Correct 485 ms 54220 KB Output is correct
7 Correct 377 ms 54220 KB Output is correct
8 Correct 474 ms 54220 KB Output is correct
9 Correct 537 ms 54220 KB Output is correct
10 Correct 631 ms 54220 KB Output is correct
11 Correct 544 ms 54220 KB Output is correct
12 Correct 613 ms 54220 KB Output is correct
13 Correct 352 ms 54220 KB Output is correct
14 Correct 597 ms 54220 KB Output is correct
15 Correct 327 ms 54220 KB Output is correct
16 Correct 408 ms 54220 KB Output is correct
17 Correct 663 ms 54220 KB Output is correct
18 Correct 379 ms 54220 KB Output is correct
19 Correct 473 ms 54220 KB Output is correct
20 Correct 662 ms 54220 KB Output is correct