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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#320594#8211. Enumerating Substringsucup-team197#AC ✓19ms34204kbC++141.2kb2024-02-03 18:28:262024-02-03 18:28:26

Judging History

你现在查看的是最新测评结果

  • [2024-02-03 18:28:26]
  • 评测
  • 测评结果:AC
  • 用时:19ms
  • 内存:34204kb
  • [2024-02-03 18:28:26]
  • 提交

answer

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll mod=1e9+7;
ll n,m,k;
ll p[1000001];
ll ways[2005];
ll dp[2005][2005];
ll C[2005];
ll pw(ll x,ll y){
	if(y==0) return 1;
	if(y%2) return x*pw(x,y-1)%mod;
	ll res=pw(x,y/2);
	return res*res%mod;
}
int main(){
	ios::sync_with_stdio(false);cin.tie(0);
	cin >> n >> m >> k;
	p[0]=1;
	for(int i=1; i<=n ;i++) p[i]=p[i-1]*k%mod;
	C[0]=1;
	for(int i=1; i<=m ;i++) C[i]=C[i-1]*(k-i+1)%mod;
	dp[0][0]=1;
	for(int i=1; i<=m ;i++){
		for(int j=i%2; j<=i ;j+=2){
			if(j!=i) dp[i][j]+=(j+1)*dp[i-1][j+1];
			if(j!=0) dp[i][j]+=dp[i-1][j-1];
			dp[i][j]%=mod;
			//cout << i << ' ' << j << ' ' << dp[i][j] << endl;
		}
	}
	ll ans=0;
	for(int i=0; i*2<=m ;i++){
		for(int r=m%2; r<=m-2*i ;r+=2){
			ways[i]+=dp[m-2*i][r]*C[(m+r)/2];
			ways[i]%=mod;
		}
	}
	for(int i=1; i<=m ;i++) ways[0]=(ways[0]+mod-ways[i])%mod;
	for(int i=0; i*2<=m ;i++){
		ll res=0;
		for(int j=1,len=m; len<=n ;j++,len+=m-i){
			if(j>1 && i==0) continue;
			ll cur=p[n-len]*(n-len+1)%mod;
			//cout << "! " << i <<' ' << j << ' ' << cur << endl;
			if(j%2) res=(res+cur)%mod;
			else res=(res+mod-cur)%mod;
		}
		ans=(ans+res*ways[i])%mod;
	}
	cout << ans << '\n';
}

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: 0ms
memory: 5748kb

input:

4 2 3

output:

228

result:

ok 1 number(s): "228"

Test #2:

score: 0
Accepted
time: 19ms
memory: 34204kb

input:

999999 1999 12345678

output:

52352722

result:

ok 1 number(s): "52352722"

Test #3:

score: 0
Accepted
time: 0ms
memory: 5796kb

input:

7 4 2

output:

182

result:

ok 1 number(s): "182"

Test #4:

score: 0
Accepted
time: 1ms
memory: 5792kb

input:

4 3 4

output:

480

result:

ok 1 number(s): "480"

Test #5:

score: 0
Accepted
time: 1ms
memory: 5784kb

input:

3 1 1

output:

3

result:

ok 1 number(s): "3"

Test #6:

score: 0
Accepted
time: 1ms
memory: 5760kb

input:

5 5 1

output:

0

result:

ok 1 number(s): "0"

Test #7:

score: 0
Accepted
time: 0ms
memory: 5688kb

input:

7 4 3

output:

5784

result:

ok 1 number(s): "5784"

Test #8:

score: 0
Accepted
time: 1ms
memory: 5672kb

input:

5 2 4

output:

3932

result:

ok 1 number(s): "3932"

Test #9:

score: 0
Accepted
time: 1ms
memory: 5676kb

input:

8 2 2

output:

1522

result:

ok 1 number(s): "1522"

Test #10:

score: 0
Accepted
time: 1ms
memory: 5668kb

input:

8 1 2

output:

2048

result:

ok 1 number(s): "2048"

Test #11:

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

input:

7 5 3

output:

2430

result:

ok 1 number(s): "2430"

Test #12:

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

input:

10 4 3

output:

272004

result:

ok 1 number(s): "272004"

Test #13:

score: 0
Accepted
time: 8ms
memory: 15736kb

input:

675978 614 2

output:

0

result:

ok 1 number(s): "0"

Test #14:

score: 0
Accepted
time: 3ms
memory: 8000kb

input:

244613 38 1

output:

0

result:

ok 1 number(s): "0"

Test #15:

score: 0
Accepted
time: 8ms
memory: 21868kb

input:

186293 1462 1

output:

0

result:

ok 1 number(s): "0"

Test #16:

score: 0
Accepted
time: 6ms
memory: 12392kb

input:

24867 886 1

output:

0

result:

ok 1 number(s): "0"

Test #17:

score: 0
Accepted
time: 12ms
memory: 20376kb

input:

976164 1014 2

output:

0

result:

ok 1 number(s): "0"

Test #18:

score: 0
Accepted
time: 3ms
memory: 7800kb

input:

179356 2 716844809

output:

577866092

result:

ok 1 number(s): "577866092"

Test #19:

score: 0
Accepted
time: 4ms
memory: 10388kb

input:

621001 130 310625363

output:

892869197

result:

ok 1 number(s): "892869197"

Test #20:

score: 0
Accepted
time: 13ms
memory: 16108kb

input:

678862 850 754662812

output:

582264789

result:

ok 1 number(s): "582264789"

Test #21:

score: 0
Accepted
time: 11ms
memory: 19460kb

input:

650845 978 348443366

output:

825425732

result:

ok 1 number(s): "825425732"

Test #22:

score: 0
Accepted
time: 6ms
memory: 13464kb

input:

669914 402 87448112

output:

318098088

result:

ok 1 number(s): "318098088"

Test #23:

score: 0
Accepted
time: 7ms
memory: 15320kb

input:

998593 530 681228665

output:

408255654

result:

ok 1 number(s): "408255654"

Test #24:

score: 0
Accepted
time: 4ms
memory: 30588kb

input:

369361 1954 125266115

output:

509912384

result:

ok 1 number(s): "509912384"

Test #25:

score: 0
Accepted
time: 13ms
memory: 25048kb

input:

900226 1378 424079373

output:

406320917

result:

ok 1 number(s): "406320917"

Test #26:

score: 0
Accepted
time: 7ms
memory: 22676kb

input:

334887 1506 17859926

output:

503264679

result:

ok 1 number(s): "503264679"

Test #27:

score: 0
Accepted
time: 11ms
memory: 14416kb

input:

936048 544 53978328

output:

548647866

result:

ok 1 number(s): "548647866"

Test #28:

score: 0
Accepted
time: 7ms
memory: 19132kb

input:

152789 1264 792983073

output:

839541707

result:

ok 1 number(s): "839541707"

Test #29:

score: 0
Accepted
time: 3ms
memory: 25032kb

input:

714493 1392 91796331

output:

721071046

result:

ok 1 number(s): "721071046"

Test #30:

score: 0
Accepted
time: 4ms
memory: 13728kb

input:

269571 816 830801077

output:

330064211

result:

ok 1 number(s): "330064211"

Test #31:

score: 0
Accepted
time: 12ms
memory: 19076kb

input:

845120 944 424581630

output:

348960190

result:

ok 1 number(s): "348960190"

Test #32:

score: 0
Accepted
time: 8ms
memory: 11816kb

input:

533990 368 163586376

output:

522092095

result:

ok 1 number(s): "522092095"

Test #33:

score: 0
Accepted
time: 8ms
memory: 25096kb

input:

181707 1792 462399634

output:

373795106

result:

ok 1 number(s): "373795106"

Test #34:

score: 0
Accepted
time: 8ms
memory: 31212kb

input:

417349 1920 761212891

output:

587051329

result:

ok 1 number(s): "587051329"

Test #35:

score: 0
Accepted
time: 8ms
memory: 22272kb

input:

526583 1344 500217637

output:

108767800

result:

ok 1 number(s): "108767800"

Test #36:

score: 0
Accepted
time: 7ms
memory: 17316kb

input:

867054 769 93998191

output:

239123369

result:

ok 1 number(s): "239123369"

Extra Test:

score: 0
Extra Test Passed