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QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#367189#6736. Alice and BobwhopxxAC ✓637ms159900kbC++14942b2024-03-25 20:06:482024-03-25 20:06:49

Judging History

你现在查看的是最新测评结果

  • [2024-03-25 20:06:49]
  • 评测
  • 测评结果:AC
  • 用时:637ms
  • 内存:159900kb
  • [2024-03-25 20:06:48]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;
#define int long long
const int mod = 998244353;
const int N = 1e7 + 10;
int a[N];
int ph[N];
int ksm(int a,int b){
    int res = 1;
    while(b){
        if(b & 1){
            res = res * a % mod;
        }
        a = a * a % mod;
        b >>= 1;
    }
    return res % mod;
}
void init(int n){
    a[0] = 1;
    for(int i = 1; i <= n; i++){
        a[i] = a[i - 1] * i % mod;
    }
}

int A(int n,int m){
    if(n - m < 0)return 0;
    return a[n] * (ph[n - m] ? ph[n - m] : ph[n - m] = ksm(a[n - m], mod - 2)) % mod;
}

void solve(){
    int n;
    cin >> n;
    init(n + 1);
    int ans = 0;
    for(int x = 1; x <= n; x++){
        ans += A(n - x,x - 1) * A(n - x,n - x) % mod;
        ans %= mod;
    }
    cout << ans % mod << '\n';
}

signed main(){
    int _(1);
    // cin >> _;
    while(_ --){
        solve();
    }
    return 0;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 0ms
memory: 3704kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 1ms
memory: 3556kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 1ms
memory: 3548kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 0ms
memory: 3588kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 0ms
memory: 3604kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 0ms
memory: 3548kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 0ms
memory: 3632kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 0ms
memory: 3540kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 0ms
memory: 3484kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 0ms
memory: 3532kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 1ms
memory: 3604kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 0ms
memory: 3532kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 0ms
memory: 3652kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 87ms
memory: 24760kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 446ms
memory: 122060kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 523ms
memory: 130928kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 389ms
memory: 99492kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 223ms
memory: 58456kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 453ms
memory: 112380kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 192ms
memory: 48744kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 582ms
memory: 159900kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 637ms
memory: 159772kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 625ms
memory: 159900kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"