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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
#119787#1084. Beautiful Sequence UnravelingCrysflyAC ✓244ms6048kbC++173.1kb2023-07-05 19:26:332023-07-05 19:26:34

Judging History

This is the latest submission verdict.

  • [2023-08-10 23:21:45]
  • System Update: QOJ starts to keep a history of the judgings of all the submissions.
  • [2023-07-05 19:26:34]
  • Judged
  • Verdict: AC
  • Time: 244ms
  • Memory: 6048kb
  • [2023-07-05 19:26:33]
  • Submitted

answer

#include<bits/stdc++.h>
#define For(i,a,b) for(int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(int i=(a);i>=(b);--i)
//#define int long long
using namespace std;
inline int read()
{
	char c=getchar();int x=0;bool f=0;
	for(;!isdigit(c);c=getchar())f^=!(c^45);
	for(;isdigit(c);c=getchar())x=(x<<1)+(x<<3)+(c^48);
	if(f)x=-x;return x;
}

int mod;
typedef unsigned long long ull;
namespace FM{
	typedef __uint128_t L;
	struct FastMod{
		ull b,m;
		FastMod(ull b):b(b),m(ull((L(1)<<64)/b)){}
		ull reduce(ull a){ull q=(ull)((L(m)*a)>>64),r=a-q*b;return r>=b?r-b:r;}
	};
	FastMod F(2);
}

struct modint{
	int x;
	modint(int o=0){x=o;}
	modint &operator = (int o){return x=o,*this;}
	modint &operator +=(modint o){return x=x+o.x>=mod?x+o.x-mod:x+o.x,*this;}
	modint &operator -=(modint o){return x=x-o.x<0?x-o.x+mod:x-o.x,*this;}
	modint &operator *=(modint o){return x=FM::F.reduce(1ull*x*o.x),*this;}
	modint &operator ^=(int b){
		modint a=*this,c=1;
		for(;b;b>>=1,a*=a)if(b&1)c*=a;
		return x=c.x,*this;
	}
	modint &operator /=(modint o){return *this *=o^=mod-2;}
	friend modint operator +(modint a,modint b){return a+=b;}
	friend modint operator -(modint a,modint b){return a-=b;}
	friend modint operator *(modint a,modint b){return a*=b;}
	friend modint operator /(modint a,modint b){return a/=b;}
	friend modint operator ^(modint a,int b){return a^=b;}
	friend bool operator ==(modint a,int b){return a.x==b;}
	friend bool operator !=(modint a,int b){return a.x!=b;}
	bool operator ! () {return !x;}
	modint operator - () {return x?mod-x:0;}
	bool operator <(const modint&b)const{return x<b.x;}
};
inline modint qpow(modint x,int y){return x^y;}
void initmod(){mod=read(),FM::F=FM::FastMod(mod);}

vector<modint> fac,ifac,iv;
inline void initC(int n)
{
	if(iv.empty())fac=ifac=iv=vector<modint>(2,1);
	int m=iv.size(); ++n;
	if(m>=n)return;
	iv.resize(n),fac.resize(n),ifac.resize(n);
	For(i,m,n-1){
		iv[i]=iv[mod%i]*(mod-mod/i);
		fac[i]=fac[i-1]*i,ifac[i]=ifac[i-1]*iv[i];
	}
}
inline modint C(int n,int m){
	if(m<0||n<m)return 0;
	return initC(n),fac[n]*ifac[m]*ifac[n-m];
}
inline modint sign(int n){return (n&1)?(mod-1):(1);}

#define fi first
#define se second
#define pb push_back
#define mkp make_pair
typedef pair<int,int>pii;
typedef vector<int>vi;

#define N 405
#define inf 0x3f3f3f3f

int n,k;

modint pw[N][N],piv[N][N];
modint f[N][N],g[N][N];
void init(int n){
	For(i,1,n){
		pw[i][0]=piv[i][0]=1;
		For(j,1,n){
			pw[i][j]=pw[i][j-1]*i;
			piv[i][j]=piv[i][j-1]*iv[i]; 
		}
	}
}

modint ans[999];
signed main()
{
	n=read(),k=read(),initmod();
	initC(405);
	init(403);
	For(i,1,n){
		For(j,1,n){
			f[i][j]=pw[j][i];
			For(x,1,j){
				modint tmp=pw[x][i]*(g[j-x+1][x]-g[j-x][x]);
				f[i][j]-=tmp;
				tmp=pw[x-1][i]*(g[j-x+1][x-1]-g[j-x][x-1]);
				f[i][j]+=tmp;
			}
		}
		For(j,1,n)
			For(x,1,n)
				g[j][x]+=f[i][j]*piv[x][i];
	}
	modint coef=1,res=0;
	For(i,1,n){
		coef*=(k-i+1);
		coef*=iv[i];
		ans[i]=f[n][i];
		For(j,1,i-1)ans[i]-=ans[j]*C(i,j);
		res+=ans[i]*coef;
	}
	cout<<res.x;
	return 0;
}

详细

Test #1:

score: 100
Accepted
time: 3ms
memory: 6048kb

input:

2 2 1000000007

output:

2

result:

ok 1 number(s): "2"

Test #2:

score: 0
Accepted
time: 2ms
memory: 6044kb

input:

3 4 1000000009

output:

36

result:

ok 1 number(s): "36"

Test #3:

score: 0
Accepted
time: 47ms
memory: 5984kb

input:

228 112263 998244353

output:

379700769

result:

ok 1 number(s): "379700769"

Test #4:

score: 0
Accepted
time: 3ms
memory: 5952kb

input:

1 1 998595277

output:

1

result:

ok 1 number(s): "1"

Test #5:

score: 0
Accepted
time: 2ms
memory: 6016kb

input:

2 2 998683811

output:

2

result:

ok 1 number(s): "2"

Test #6:

score: 0
Accepted
time: 1ms
memory: 5948kb

input:

3 1 998277223

output:

0

result:

ok 1 number(s): "0"

Test #7:

score: 0
Accepted
time: 2ms
memory: 5948kb

input:

4 1 998365733

output:

0

result:

ok 1 number(s): "0"

Test #8:

score: 0
Accepted
time: 244ms
memory: 6048kb

input:

400 100000000 998244353

output:

318973800

result:

ok 1 number(s): "318973800"

Test #9:

score: 0
Accepted
time: 244ms
memory: 5992kb

input:

400 1 1000000007

output:

0

result:

ok 1 number(s): "0"

Test #10:

score: 0
Accepted
time: 2ms
memory: 6048kb

input:

2 9 999603883

output:

72

result:

ok 1 number(s): "72"

Test #11:

score: 0
Accepted
time: 3ms
memory: 5948kb

input:

1 1 998784541

output:

1

result:

ok 1 number(s): "1"

Test #12:

score: 0
Accepted
time: 0ms
memory: 5952kb

input:

3 3 999209353

output:

12

result:

ok 1 number(s): "12"

Test #13:

score: 0
Accepted
time: 2ms
memory: 5988kb

input:

4 12 999787531

output:

16544

result:

ok 1 number(s): "16544"

Test #14:

score: 0
Accepted
time: 244ms
memory: 6000kb

input:

400 3 998785127

output:

505031599

result:

ok 1 number(s): "505031599"

Test #15:

score: 0
Accepted
time: 244ms
memory: 6016kb

input:

400 77 999400643

output:

877578741

result:

ok 1 number(s): "877578741"

Test #16:

score: 0
Accepted
time: 240ms
memory: 5952kb

input:

400 374 998458939

output:

202865317

result:

ok 1 number(s): "202865317"

Test #17:

score: 0
Accepted
time: 240ms
memory: 5924kb

input:

400 77435643 999245677

output:

833344996

result:

ok 1 number(s): "833344996"

Test #18:

score: 0
Accepted
time: 239ms
memory: 6016kb

input:

399 72119824 999010279

output:

188282648

result:

ok 1 number(s): "188282648"

Test #19:

score: 0
Accepted
time: 240ms
memory: 5956kb

input:

398 22521432 999827603

output:

986913334

result:

ok 1 number(s): "986913334"

Test #20:

score: 0
Accepted
time: 219ms
memory: 6040kb

input:

397 77955743 998803427

output:

32764673

result:

ok 1 number(s): "32764673"