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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#526421#8211. Enumerating Substringsucup-team3792AC ✓32ms23284kbC++141.4kb2024-08-21 15:37:482024-08-21 15:37:49

Judging History

你现在查看的是最新测评结果

  • [2024-08-21 15:37:49]
  • 评测
  • 测评结果:AC
  • 用时:32ms
  • 内存:23284kb
  • [2024-08-21 15:37:48]
  • 提交

answer

#include<bits/stdc++.h>
using namespace std;
const int mod=1e9+7;
int n,m,k,f[2005],g[2005],ans,pw[2005],ipw[2005],pwk[1000005];
int fac[2005],inv[2005],dn[2005][2005];
int qpow(int a,int b)
{
	if(b==0) return 1;
	int g=qpow(a,b/2);
	g=1ll*g*g%mod;
	if(b&1) g=1ll*g*a%mod;
	return g;
}
int calc(int x)
{
	if(x>n) return 0;
	return 1ll*(n-x+1)*pwk[n-x]%mod;
}
int C(int n,int m)
{
	if(n<m) return 0;
	return 1ll*dn[k-n+1][m]*inv[m]%mod;
}
int main()
{
	cin>>n>>m>>k;
	fac[0]=inv[0]=pw[0]=ipw[0]=pwk[0]=1;
	for(int i=1;i<=m;i++)
	{
		fac[i]=1ll*fac[i-1]*i%mod;
		inv[i]=qpow(fac[i],mod-2);
		pw[i]=1ll*pw[i-1]*2%mod;
		ipw[i]=qpow(pw[i],mod-2);
	}
	for(int i=1;i<=n;i++)
	{
		pwk[i]=1ll*pwk[i-1]*k%mod;
	}
	for(int i=1;i<=m;i++)
	{
		dn[i][0]=1;
		dn[i][1]=(k-i+1);
		for(int j=1;j<=m;j++)
		{
			dn[i][j+1]=1ll*dn[i][j]*(k-i+1-j)%mod;
		}
	}
	for(int i=0;i*2<=m;i++)
	{
		if(i==0) g[i]=calc(m);
		else
		{
			int c=1;
			for(int j=m;j<=n;j+=m-i)
			{
				g[i]+=1ll*c*calc(j)%mod;
				if(g[i]>=mod) g[i]-=mod;
				c=mod-c;
			}
		}
		int w=1ll*C(k,i)*fac[i]%mod,sum=0;
		for(int j=0;i*2+j*2<=m;j++)
		{
			sum+=1ll*C(k-i,j)*C(k-i-j,m-i*2-j*2)%mod*fac[m-i*2]%mod*ipw[j]%mod;
			if(sum>=mod) sum-=mod;
		}
		f[i]=1ll*w*sum%mod;
	}
	for(int i=1;i*2<=m;i++)
	{
		f[0]-=f[i];
		if(f[0]<0) f[0]+=mod;
	}
	for(int i=0;i*2<=m;i++)
	{
		ans+=1ll*f[i]*g[i]%mod;
		if(ans>=mod) ans-=mod;
	}
	cout<<ans;
}

这程序好像有点Bug,我给组数据试试?

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 1ms
memory: 5676kb

input:

4 2 3

output:

228

result:

ok 1 number(s): "228"

Test #2:

score: 0
Accepted
time: 32ms
memory: 23284kb

input:

999999 1999 12345678

output:

52352722

result:

ok 1 number(s): "52352722"

Test #3:

score: 0
Accepted
time: 0ms
memory: 5780kb

input:

7 4 2

output:

182

result:

ok 1 number(s): "182"

Test #4:

score: 0
Accepted
time: 0ms
memory: 5768kb

input:

4 3 4

output:

480

result:

ok 1 number(s): "480"

Test #5:

score: 0
Accepted
time: 0ms
memory: 5724kb

input:

3 1 1

output:

3

result:

ok 1 number(s): "3"

Test #6:

score: 0
Accepted
time: 1ms
memory: 5584kb

input:

5 5 1

output:

0

result:

ok 1 number(s): "0"

Test #7:

score: 0
Accepted
time: 1ms
memory: 5700kb

input:

7 4 3

output:

5784

result:

ok 1 number(s): "5784"

Test #8:

score: 0
Accepted
time: 0ms
memory: 5764kb

input:

5 2 4

output:

3932

result:

ok 1 number(s): "3932"

Test #9:

score: 0
Accepted
time: 1ms
memory: 5680kb

input:

8 2 2

output:

1522

result:

ok 1 number(s): "1522"

Test #10:

score: 0
Accepted
time: 1ms
memory: 5768kb

input:

8 1 2

output:

2048

result:

ok 1 number(s): "2048"

Test #11:

score: 0
Accepted
time: 1ms
memory: 5592kb

input:

7 5 3

output:

2430

result:

ok 1 number(s): "2430"

Test #12:

score: 0
Accepted
time: 1ms
memory: 5584kb

input:

10 4 3

output:

272004

result:

ok 1 number(s): "272004"

Test #13:

score: 0
Accepted
time: 10ms
memory: 13552kb

input:

675978 614 2

output:

0

result:

ok 1 number(s): "0"

Test #14:

score: 0
Accepted
time: 2ms
memory: 5832kb

input:

244613 38 1

output:

0

result:

ok 1 number(s): "0"

Test #15:

score: 0
Accepted
time: 14ms
memory: 19840kb

input:

186293 1462 1

output:

0

result:

ok 1 number(s): "0"

Test #16:

score: 0
Accepted
time: 5ms
memory: 14488kb

input:

24867 886 1

output:

0

result:

ok 1 number(s): "0"

Test #17:

score: 0
Accepted
time: 16ms
memory: 17132kb

input:

976164 1014 2

output:

0

result:

ok 1 number(s): "0"

Test #18:

score: 0
Accepted
time: 2ms
memory: 7672kb

input:

179356 2 716844809

output:

577866092

result:

ok 1 number(s): "577866092"

Test #19:

score: 0
Accepted
time: 7ms
memory: 9932kb

input:

621001 130 310625363

output:

892869197

result:

ok 1 number(s): "892869197"

Test #20:

score: 0
Accepted
time: 9ms
memory: 16144kb

input:

678862 850 754662812

output:

582264789

result:

ok 1 number(s): "582264789"

Test #21:

score: 0
Accepted
time: 13ms
memory: 17796kb

input:

650845 978 348443366

output:

825425732

result:

ok 1 number(s): "825425732"

Test #22:

score: 0
Accepted
time: 0ms
memory: 12532kb

input:

669914 402 87448112

output:

318098088

result:

ok 1 number(s): "318098088"

Test #23:

score: 0
Accepted
time: 6ms
memory: 14660kb

input:

998593 530 681228665

output:

408255654

result:

ok 1 number(s): "408255654"

Test #24:

score: 0
Accepted
time: 27ms
memory: 21316kb

input:

369361 1954 125266115

output:

509912384

result:

ok 1 number(s): "509912384"

Test #25:

score: 0
Accepted
time: 21ms
memory: 20848kb

input:

900226 1378 424079373

output:

406320917

result:

ok 1 number(s): "406320917"

Test #26:

score: 0
Accepted
time: 17ms
memory: 20280kb

input:

334887 1506 17859926

output:

503264679

result:

ok 1 number(s): "503264679"

Test #27:

score: 0
Accepted
time: 8ms
memory: 12844kb

input:

936048 544 53978328

output:

548647866

result:

ok 1 number(s): "548647866"

Test #28:

score: 0
Accepted
time: 12ms
memory: 16288kb

input:

152789 1264 792983073

output:

839541707

result:

ok 1 number(s): "839541707"

Test #29:

score: 0
Accepted
time: 15ms
memory: 20348kb

input:

714493 1392 91796331

output:

721071046

result:

ok 1 number(s): "721071046"

Test #30:

score: 0
Accepted
time: 8ms
memory: 15596kb

input:

269571 816 830801077

output:

330064211

result:

ok 1 number(s): "330064211"

Test #31:

score: 0
Accepted
time: 14ms
memory: 16492kb

input:

845120 944 424581630

output:

348960190

result:

ok 1 number(s): "348960190"

Test #32:

score: 0
Accepted
time: 7ms
memory: 11148kb

input:

533990 368 163586376

output:

522092095

result:

ok 1 number(s): "522092095"

Test #33:

score: 0
Accepted
time: 22ms
memory: 21024kb

input:

181707 1792 462399634

output:

373795106

result:

ok 1 number(s): "373795106"

Test #34:

score: 0
Accepted
time: 26ms
memory: 21020kb

input:

417349 1920 761212891

output:

587051329

result:

ok 1 number(s): "587051329"

Test #35:

score: 0
Accepted
time: 17ms
memory: 20036kb

input:

526583 1344 500217637

output:

108767800

result:

ok 1 number(s): "108767800"

Test #36:

score: 0
Accepted
time: 14ms
memory: 14352kb

input:

867054 769 93998191

output:

239123369

result:

ok 1 number(s): "239123369"

Extra Test:

score: 0
Extra Test Passed