QOJ.ac
QOJ
| 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 |
|---|---|---|---|---|---|---|---|---|---|
| #157019 | #6736. Alice and Bob | messi_esn | TL | 901ms | 81856kb | C++17 | 674b | 2023-09-02 14:46:58 | 2023-09-02 15:00:04 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
const int N=1e7+10, mod = 998244353;
typedef long long ll;
ll res[N];
void init()
{
for(int i = 1; i <= N; i++)
{
res[i] = (res[i-1] * i) % mod;
}
}
ll qpow(ll a, ll b)
{
ll ans = 1;
while(b)
{
if(b & 1)
ans = (ans * a) % mod;
a = (a * a) % mod;
b>>=1;
}
return ans%mod;
}
ll A(int n, int m)
{
return (res[n]*qpow(res[n-m],mod-2))%mod;
}
int main()
{
res[0] = 1;
init();
int n;
cin >> n;
int len = n / 2;
if(n%2)
len++;
long long sum = 0;
for(int i = 1; i <= len; i++)
{
sum =(sum + (A(n-i,i-1) * A(n-i,n-i)) %mod)%mod;
}
cout << sum;
}
详细
Test #1:
score: 100
Accepted
time: 30ms
memory: 81776kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 42ms
memory: 81828kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 35ms
memory: 81772kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 39ms
memory: 81776kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 35ms
memory: 81772kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 38ms
memory: 81656kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 30ms
memory: 81776kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 35ms
memory: 81768kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 39ms
memory: 81856kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 51ms
memory: 81704kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 36ms
memory: 81832kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 48ms
memory: 81840kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 32ms
memory: 81844kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 169ms
memory: 81704kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 846ms
memory: 81772kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 901ms
memory: 81736kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 688ms
memory: 81656kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 428ms
memory: 81772kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 793ms
memory: 81656kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 347ms
memory: 81700kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: -100
Time Limit Exceeded
input:
9999998