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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
#204400#6736. Alice and BobkiwiHM#AC ✓108ms82052kbC++14861b2023-10-07 11:06:412023-10-07 11:06:43

Judging History

你现在查看的是最新测评结果

  • [2023-10-07 11:06:43]
  • 评测
  • 测评结果:AC
  • 用时:108ms
  • 内存:82052kb
  • [2023-10-07 11:06:41]
  • 提交

answer

#include <bits/stdc++.h>

using namespace std;

const int maxn = 1e7 + 5;
const int INF = 998244353;

int n;
int fac[maxn], ifac[maxn];

inline int qpow(int x, int y){
	int ret = 1;
	for(; y; y >>= 1){
		if(y & 1) ret = 1ll * ret * x % INF;
		x = 1ll * x * x % INF;
	}
	return ret;
}

inline int binom(int x, int y){
	if(x > y) return 0;
	return 1ll * fac[x] * ifac[y] % INF * ifac[x - y] % INF;
}

int main(){
	scanf("%d", &n);
	fac[0] = 1; for(int i = 1; i <= n; ++i) fac[i] = 1ll * fac[i - 1] * i % INF;
	ifac[n] = qpow(fac[n], INF - 2); for(int i = n - 1; i >= 0; --i) ifac[i] = 1ll * ifac[i + 1] * (i + 1) % INF;
	int ans = 0;
	for(int i = 1; i <= n; ++i) if(n - i >= i - 1){
		int res = 1ll * fac[n - i] * ifac[(n - i) - (i - 1)] % INF * fac[n - i] % INF;
		ans = (ans + res) % INF;
	}
	printf("%d\n", ans);
	return 0;
}

详细

Test #1:

score: 100
Accepted
time: 1ms
memory: 5916kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 1ms
memory: 5920kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 1ms
memory: 5848kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 1ms
memory: 5904kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 1ms
memory: 5984kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 1ms
memory: 5972kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 0ms
memory: 5900kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 0ms
memory: 5968kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 0ms
memory: 5920kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 1ms
memory: 5840kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 0ms
memory: 5844kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 1ms
memory: 5816kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 0ms
memory: 5888kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 17ms
memory: 19192kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 69ms
memory: 64512kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 94ms
memory: 68704kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 67ms
memory: 52588kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 30ms
memory: 34088kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 72ms
memory: 60476kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 31ms
memory: 31400kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 96ms
memory: 82036kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 108ms
memory: 82028kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 104ms
memory: 82052kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"