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ID题目提交者结果用时内存语言文件大小提交时间测评时间
#397143#6678. Gem Island 2zhouhuanyiWA 267ms240424kbC++141.4kb2024-04-23 17:34:562024-04-23 17:34:57

Judging History

你现在查看的是最新测评结果

  • [2024-04-23 17:43:38]
  • hack成功,自动添加数据
  • (/hack/600)
  • [2024-04-23 17:34:57]
  • 评测
  • 测评结果:WA
  • 用时:267ms
  • 内存:240424kb
  • [2024-04-23 17:34:56]
  • 提交

answer

#include<iostream>
#include<cstdio>
#define N 30000000
#define mod 998244353
using namespace std;
int read()
{
	char c=0;
	int sum=0;
	while (c<'0'||c>'9') c=getchar();
	while ('0'<=c&&c<='9') sum=sum*10+c-'0',c=getchar();
	return sum;
}
int fast_pow(int a,int b)
{
	int res=1,mul=a;
	while (b)
	{
		if (b&1) res=1ll*res*mul%mod;
		mul=1ll*mul*mul%mod,b>>=1;
	}
	return res;
}
int MD(int x)
{
	return x>=mod?x-mod:x;
}
int MD2(int x)
{
	return x<0?x+mod:x;
}
void Adder(int &x,int d)
{
	x+=d;
	if (x>=mod) x-=mod;
	return;
}
void Adder2(int &x,int d)
{
	x+=d;
	if (x<0) x+=mod;
	return;
}
int n,d,r,F[N+1],G[N+1],fac[N+1],invfac[N+1],ans;
int C(int x,int y)
{
	return 1ll*fac[x]*invfac[y]%mod*invfac[x-y]%mod;
}
int main()
{
	int res;
	fac[0]=1;
	for (int i=1;i<=N;++i) fac[i]=1ll*fac[i-1]*i%mod;
	invfac[N]=fast_pow(fac[N],mod-2);
	for (int i=N-1;i>=0;--i) invfac[i]=1ll*invfac[i+1]*(i+1)%mod;
	n=read(),d=read(),r=read(),F[1]=1;
	for (int i=r+1;i<=n;++i)
	{
		if (!((i-r)&1)) F[i]=C(i-2,r-1);
		else F[i]=MD2(-C(i-2,r-1));
	}
	for (int i=1;i<=n;++i) F[i]=1ll*F[i]*C(n,i)%mod;
	for (int i=0;i<=d;++i) G[i]=C(n-1+d-i,n-1);
	for (int i=1;i<=n;++i)
	{
		res=0;
		for (int j=1;j<=min(n,d/i);++j) Adder(res,G[i*j]);
		Adder(ans,1ll*F[i]*res%mod);
	}
	printf("%d\n",MD(1ll*ans*fast_pow(C(n-1+d,n-1),mod-2)%mod+r));
	return 0;
}

详细

Test #1:

score: 0
Wrong Answer
time: 267ms
memory: 240424kb

input:

2 3 1

output:

3

result:

wrong answer 1st numbers differ - expected: '499122180', found: '3'