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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
#129273#6736. Alice and BobSolitaryDream#AC ✓124ms159876kbC++20802b2023-07-22 13:26:262023-07-22 13:26:28

Judging History

你现在查看的是最新测评结果

  • [2023-08-10 23:21:45]
  • System Update: QOJ starts to keep a history of the judgings of all the submissions.
  • [2023-07-22 13:26:28]
  • 评测
  • 测评结果:AC
  • 用时:124ms
  • 内存:159876kb
  • [2023-07-22 13:26:26]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;
#define FOR(i,s,t) for(int i=(s),_t=(t); i<=_t; ++i)
#define DOR(i,s,t) for(int i=(s),_t=(t); i>=_t; --i)
typedef long long ll;
const int Mod=998244353;
ll Fast(ll x,int b) {
    ll t=1;
    for(; b; b>>=1,x=x*x%Mod) if(b&1) t=t*x%Mod;
    return t;
}
const int N=1e7+50;
ll Fac[N],Inv[N];
ll C(int n,int m) {
    if(n<m) return 0;
    return Fac[n]*Inv[n-m]%Mod*Inv[m]%Mod;
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;
    cin >> n;
    Fac[0]=1;
    FOR(i,1,n) Fac[i]=Fac[i-1]*i%Mod;
    Inv[n]=Fast(Fac[n],Mod-2);
    DOR(i,n,1) Inv[i-1]=Inv[i]*i%Mod;
    ll res=0;
    FOR(i,1,n) {
        res=(res+C(n-i,i-1)*Fac[i-1]%Mod*Fac[n-i])%Mod;
    }
    cout << res << '\n';
    return 0;
}

详细

Test #1:

score: 100
Accepted
time: 1ms
memory: 5520kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 1ms
memory: 5492kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 1ms
memory: 5508kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 1ms
memory: 5504kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 1ms
memory: 5624kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 1ms
memory: 5576kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 1ms
memory: 5640kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 1ms
memory: 5648kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 1ms
memory: 5528kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 0ms
memory: 5516kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 1ms
memory: 5504kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 1ms
memory: 5516kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

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

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 12ms
memory: 28248kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 88ms
memory: 126272kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 99ms
memory: 133728kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 56ms
memory: 100848kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 37ms
memory: 60716kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 88ms
memory: 116572kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 41ms
memory: 52424kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 100ms
memory: 159728kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 120ms
memory: 159876kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 124ms
memory: 159660kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"