Submission #994849


Source Code Expand

//*
#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;

ll n, m;

ll fac[200000];

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;
}

ll ncr(ll n, ll r)
{
	if(n < r) return 0;
	return fac[n]*mul_inv(fac[r])%MOD*mul_inv(fac[n-r])%MOD;
}

ll d[400][400];

int main()
{
	ll i, j, k, l;
	cin>>n>>m;
	fac[0]=1;
	for(i=1;i<200000;i++) fac[i]=fac[i-1]*i, fac[i]%=MOD;
	ll ans=0;
	d[0][1]=1;
	for(i=0;i<m;i++)
	{
		for(j=1;j<=n;j++)
		{
			d[i+1][j]+=d[i][j]*j%MOD;
			d[i+1][j+1]+=d[i][j]*(n-j)%MOD;
			d[i+1][j]%=MOD, d[i+1][j+1]%=MOD;
		}
	}
	for(i=n-1;i<m;i++)
	{
		ll t=i;
		ll u=modpow(n-1, m-1-i)%MOD;
		ll sum=0;
		/*for(j=0;j<=n-1;j++)
		{
			sum+=modpow(n-j, t)*ncr(n-1, j)%MOD*(j%2==0?1:-1)%MOD;
			sum%=MOD;
		}
		ans+=sum*u%MOD;*/
		ans+=d[t][n]*u%MOD;
		ans%=MOD;
	}
	if(ans < 0) ans+=MOD;
	cout<<ans<<endl;
	return 0;
}
//*/

Submission Info

Submission Time
Task F - Road of the King
User polequoll
Language C++14 (GCC 5.4.1)
Score 0
Code Size 1749 Byte
Status WA
Exec Time 7 ms
Memory 2688 KB

Judge Result

Set Name sample all
Score / Max Score 0 / 0 0 / 1000
Status
AC × 2
WA × 1
AC × 7
WA × 6
Set Name Test Cases
sample sample-01.txt, sample-02.txt, sample-03.txt
all sample-01.txt, sample-02.txt, sample-03.txt, 01-01.txt, 01-02.txt, 01-03.txt, 01-04.txt, 01-05.txt, 01-06.txt, 01-07.txt, 01-08.txt, 01-09.txt, 01-10.txt
Case Name Status Exec Time Memory
01-01.txt AC 5 ms 1792 KB
01-02.txt AC 5 ms 1792 KB
01-03.txt AC 7 ms 2688 KB
01-04.txt AC 5 ms 1792 KB
01-05.txt WA 7 ms 2688 KB
01-06.txt WA 7 ms 2688 KB
01-07.txt WA 7 ms 2688 KB
01-08.txt WA 7 ms 2688 KB
01-09.txt WA 7 ms 2688 KB
01-10.txt AC 7 ms 2688 KB
sample-01.txt AC 5 ms 1792 KB
sample-02.txt WA 7 ms 2688 KB
sample-03.txt AC 6 ms 2304 KB