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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
#590951#8635. 圆xiay20 41ms3852kbC++14695b2024-09-26 13:15:132024-09-26 13:15:15

Judging History

你现在查看的是最新测评结果

  • [2024-09-26 13:15:15]
  • 评测
  • 测评结果:20
  • 用时:41ms
  • 内存:3852kb
  • [2024-09-26 13:15:13]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;

const int N = 5000 + 5, P = 998244353;
int dp[N], n;

long long qpow(long long a, int b) {
	long long ans = 1;
	while (b) {
		if (b & 1) {
			ans = ans * a % P;
		}
		a = a * a % P;
		b >>= 1;
	}
	return ans;
}

int main() {
	#ifndef ONLINE_JUDGE
	freopen("test.in", "r", stdin);
	freopen("test.out", "w", stdout);
	#endif

	scanf("%d", &n);
	dp[1] = 0;
	dp[2] = 0; 
	for (int i = 3; i <= n - 1; i++) {
		int sum = 0;
		for (int j = 1; j <= i; j++) {
			sum = (sum + (dp[j - 1] + dp[i - j]) % P) % P;
		}
		sum = 1ll * sum * qpow(i, P - 2) % P;
		dp[i] = sum + 1;
	}
	printf("%d", dp[n - 1] + 1);

	return 0;
}

详细


Pretests


Final Tests

Test #1:

score: 10
Accepted
time: 0ms
memory: 3840kb

input:

3

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 10
Accepted
time: 0ms
memory: 3812kb

input:

4

output:

2

result:

ok 1 number(s): "2"

Test #3:

score: 0
Wrong Answer
time: 0ms
memory: 3792kb

input:

6

output:

3

result:

wrong answer 1st numbers differ - expected: '299473309', found: '3'

Test #4:

score: 0
Wrong Answer
time: 0ms
memory: 3764kb

input:

10

output:

5

result:

wrong answer 1st numbers differ - expected: '487238321', found: '5'

Test #5:

score: 0
Wrong Answer
time: 0ms
memory: 3724kb

input:

100

output:

50

result:

wrong answer 1st numbers differ - expected: '41620761', found: '50'

Test #6:

score: 0
Wrong Answer
time: 0ms
memory: 3652kb

input:

200

output:

100

result:

wrong answer 1st numbers differ - expected: '208771764', found: '100'

Test #7:

score: 0
Wrong Answer
time: 1ms
memory: 3792kb

input:

500

output:

250

result:

wrong answer 1st numbers differ - expected: '888621375', found: '250'

Test #8:

score: 0
Wrong Answer
time: 34ms
memory: 3664kb

input:

4798

output:

2399

result:

wrong answer 1st numbers differ - expected: '319137015', found: '2399'

Test #9:

score: 0
Wrong Answer
time: 41ms
memory: 3832kb

input:

4999

output:

499124676

result:

wrong answer 1st numbers differ - expected: '818467659', found: '499124676'

Test #10:

score: 0
Wrong Answer
time: 37ms
memory: 3852kb

input:

5000

output:

2500

result:

wrong answer 1st numbers differ - expected: '142907477', found: '2500'