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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#185873#4812. Counting SequenceDualqwqAC ✓2036ms20552kbC++141.3kb2023-09-22 18:17:392023-09-22 18:17:39

Judging History

你现在查看的是最新测评结果

  • [2023-09-22 18:17:39]
  • 评测
  • 测评结果:AC
  • 用时:2036ms
  • 内存:20552kb
  • [2023-09-22 18:17:39]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;
const int N = 5e5 + 5,B = 780,P = 998244353;
inline void Plus(int &x,const int &y) { x += y;if(x >= P) x -= P;}
int dp[B * 2 + 5][B * 2 + 5];
int n,c;
inline int Solve1() {
	for(int i = 1;i < B;i++) 
		dp[i][i] = 1;
	int mod = B * 2 + 5;
	for(int i = 1;i < n;i++) {
		for(int j = 1;j <= B * 2;j++) {
			int now = i % mod,nxt = (i + j + 1) % mod,val = dp[now][j];
			dp[now][j] = 0;if(!val) continue;
			Plus(dp[nxt][j + 1],val);
			nxt = (i + j - 1) % mod;
			if(j != 1) nxt = (i + j - 1) % mod,Plus(dp[nxt][j - 1],1ll * c * val % P);
		}
	}
	int ans = 0;
	for(int i = 1;i <= 2 * B;i++) Plus(ans,dp[n % mod][i]);
	return ans;
}
int f[2][N << 1];
inline int Solve2() {
	f[0][N] = 1;
	int ans = 0;
	for(int i = 1;i <= B;i++) {
		int lim = i * (i - 1) / 2;
		for(int j = N - lim;j <= N + lim;j++) f[i&1][j] = 0;
		for(int j = N - lim;j <= N + lim;j++) {
			if(i > 1) Plus(f[i&1][j - (i - 1)],1ll * f[(i-1)&1][j] * c % P);
			Plus(f[i&1][j + (i - 1)],f[(i-1)&1][j]);
		}
		for(int j = B;j <= n;j++) { // 枚举 a[1]
			int tmp = n - i * j;
			if(abs(tmp) <= lim) Plus(ans,f[i&1][tmp + N]);
		}
	}
	return ans;
}
int main() {
	cin >> n >> c;
	int ans = Solve1();
	Plus(ans,Solve2());
	cout << ans << endl;
	return 0;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 285ms
memory: 15940kb

input:

5 3

output:

8

result:

ok 1 number(s): "8"

Test #2:

score: 0
Accepted
time: 295ms
memory: 15800kb

input:

1 0

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 278ms
memory: 19300kb

input:

2022 39

output:

273239559

result:

ok 1 number(s): "273239559"

Test #4:

score: 0
Accepted
time: 286ms
memory: 16704kb

input:

1 998244352

output:

1

result:

ok 1 number(s): "1"

Test #5:

score: 0
Accepted
time: 290ms
memory: 14804kb

input:

1 12345678

output:

1

result:

ok 1 number(s): "1"

Test #6:

score: 0
Accepted
time: 287ms
memory: 16216kb

input:

20 998998

output:

643731701

result:

ok 1 number(s): "643731701"

Test #7:

score: 0
Accepted
time: 287ms
memory: 16732kb

input:

23 123

output:

947753998

result:

ok 1 number(s): "947753998"

Test #8:

score: 0
Accepted
time: 291ms
memory: 14260kb

input:

50 5555

output:

745339864

result:

ok 1 number(s): "745339864"

Test #9:

score: 0
Accepted
time: 290ms
memory: 16724kb

input:

60 6666

output:

690992218

result:

ok 1 number(s): "690992218"

Test #10:

score: 0
Accepted
time: 290ms
memory: 14428kb

input:

100 50

output:

169678588

result:

ok 1 number(s): "169678588"

Test #11:

score: 0
Accepted
time: 290ms
memory: 16236kb

input:

500 88888

output:

216149701

result:

ok 1 number(s): "216149701"

Test #12:

score: 0
Accepted
time: 286ms
memory: 17852kb

input:

1000 213456

output:

270989457

result:

ok 1 number(s): "270989457"

Test #13:

score: 0
Accepted
time: 288ms
memory: 20036kb

input:

2000 119988

output:

756425375

result:

ok 1 number(s): "756425375"

Test #14:

score: 0
Accepted
time: 297ms
memory: 20048kb

input:

3000 998244352

output:

71841227

result:

ok 1 number(s): "71841227"

Test #15:

score: 0
Accepted
time: 304ms
memory: 20212kb

input:

3000 555555555

output:

79880116

result:

ok 1 number(s): "79880116"

Test #16:

score: 0
Accepted
time: 298ms
memory: 18508kb

input:

4321 1234

output:

949603993

result:

ok 1 number(s): "949603993"

Test #17:

score: 0
Accepted
time: 288ms
memory: 19008kb

input:

5000 0

output:

5

result:

ok 1 number(s): "5"

Test #18:

score: 0
Accepted
time: 302ms
memory: 18764kb

input:

5000 88888777

output:

833064960

result:

ok 1 number(s): "833064960"

Test #19:

score: 0
Accepted
time: 296ms
memory: 18976kb

input:

5000 35557777

output:

696388498

result:

ok 1 number(s): "696388498"

Test #20:

score: 0
Accepted
time: 321ms
memory: 18616kb

input:

10000 123456

output:

434296902

result:

ok 1 number(s): "434296902"

Test #21:

score: 0
Accepted
time: 359ms
memory: 18848kb

input:

20000 555555

output:

34806915

result:

ok 1 number(s): "34806915"

Test #22:

score: 0
Accepted
time: 417ms
memory: 18520kb

input:

30000 777888999

output:

58443551

result:

ok 1 number(s): "58443551"

Test #23:

score: 0
Accepted
time: 497ms
memory: 18720kb

input:

50000 2

output:

90102905

result:

ok 1 number(s): "90102905"

Test #24:

score: 0
Accepted
time: 604ms
memory: 18572kb

input:

70000 77998866

output:

202638568

result:

ok 1 number(s): "202638568"

Test #25:

score: 0
Accepted
time: 726ms
memory: 18892kb

input:

100000 998244352

output:

360520717

result:

ok 1 number(s): "360520717"

Test #26:

score: 0
Accepted
time: 732ms
memory: 18520kb

input:

100000 555555555

output:

613886009

result:

ok 1 number(s): "613886009"

Test #27:

score: 0
Accepted
time: 1003ms
memory: 20044kb

input:

150000 233333

output:

381065878

result:

ok 1 number(s): "381065878"

Test #28:

score: 0
Accepted
time: 970ms
memory: 20552kb

input:

150000 20050117

output:

269891864

result:

ok 1 number(s): "269891864"

Test #29:

score: 0
Accepted
time: 1272ms
memory: 18776kb

input:

200000 114514

output:

262861613

result:

ok 1 number(s): "262861613"

Test #30:

score: 0
Accepted
time: 1281ms
memory: 18596kb

input:

200000 1919810

output:

77872388

result:

ok 1 number(s): "77872388"

Test #31:

score: 0
Accepted
time: 686ms
memory: 20044kb

input:

300000 0

output:

12

result:

ok 1 number(s): "12"

Test #32:

score: 0
Accepted
time: 1879ms
memory: 18508kb

input:

300000 1

output:

298803948

result:

ok 1 number(s): "298803948"

Test #33:

score: 0
Accepted
time: 1953ms
memory: 19932kb

input:

300000 2

output:

106751203

result:

ok 1 number(s): "106751203"

Test #34:

score: 0
Accepted
time: 2036ms
memory: 19272kb

input:

300000 1234

output:

427045479

result:

ok 1 number(s): "427045479"

Test #35:

score: 0
Accepted
time: 1953ms
memory: 20044kb

input:

300000 2345

output:

441593553

result:

ok 1 number(s): "441593553"

Test #36:

score: 0
Accepted
time: 2029ms
memory: 20044kb

input:

300000 20041115

output:

580367993

result:

ok 1 number(s): "580367993"

Test #37:

score: 0
Accepted
time: 1945ms
memory: 18468kb

input:

300000 20050117

output:

579859619

result:

ok 1 number(s): "579859619"

Test #38:

score: 0
Accepted
time: 1924ms
memory: 20044kb

input:

300000 22223333

output:

596066085

result:

ok 1 number(s): "596066085"

Test #39:

score: 0
Accepted
time: 1993ms
memory: 18644kb

input:

300000 175846372

output:

660364393

result:

ok 1 number(s): "660364393"

Test #40:

score: 0
Accepted
time: 1941ms
memory: 20268kb

input:

299999 9999999

output:

954865020

result:

ok 1 number(s): "954865020"

Test #41:

score: 0
Accepted
time: 1834ms
memory: 18832kb

input:

299998 55556666

output:

904862432

result:

ok 1 number(s): "904862432"

Test #42:

score: 0
Accepted
time: 1228ms
memory: 20048kb

input:

190733 31756136

output:

880544587

result:

ok 1 number(s): "880544587"

Test #43:

score: 0
Accepted
time: 1326ms
memory: 19132kb

input:

198497 463488298

output:

185220207

result:

ok 1 number(s): "185220207"

Test #44:

score: 0
Accepted
time: 666ms
memory: 19996kb

input:

299997 0

output:

16

result:

ok 1 number(s): "16"

Test #45:

score: 0
Accepted
time: 1146ms
memory: 20040kb

input:

168168 296157813

output:

798716760

result:

ok 1 number(s): "798716760"

Test #46:

score: 0
Accepted
time: 825ms
memory: 18892kb

input:

114514 1919810

output:

783513290

result:

ok 1 number(s): "783513290"