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 |
---|---|---|---|---|---|---|---|---|---|
#350641 | #6736. Alice and Bob | Albert711 | AC ✓ | 682ms | 159920kb | C++20 | 1.6kb | 2024-03-10 22:27:40 | 2024-03-10 22:27:40 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef double db;
const int N = 1e7 + 5;
const int mod = 998244353;
//#define int long long
using i64 = int64_t;
i64 fpow(i64 x, i64 r) {
i64 result = 1;
while (r) {
if (r & 1)result = result * x % mod;
r >>= 1;
x = x * x % mod;
}
return result;
}
namespace binom {
i64 fac[N], ifac[N];
int __ = [] {
fac[0] = 1;
for (int i = 1; i <= N - 5; i++)
fac[i] = fac[i - 1] * i % mod;
ifac[N - 5] = fpow(fac[N - 5], mod - 2);
for (int i = N - 5; i; i--)
ifac[i - 1] = ifac[i] * i % mod;
return 0;
}();
inline i64 C(int n, int m) {
if (n < m || m < 0)return 0;
return fac[n] * ifac[m] % mod * ifac[n - m] % mod;
}
inline i64 A(int n, int m) {
if (n < m || m < 0)return 0;
return fac[n] * ifac[n - m] % mod;
}
}
using namespace binom;
void solve() {
ll n;
cin >> n;
if(n==1) {
cout<<1<<'\n';
return;
}
ll ans = 0;
ll tmp = 1;
for (int i = 1; i <= n - 1; i++) tmp = tmp * i % mod;
ll tt = tmp;
for (int i = 1; i <= n; i++) {
if (i - 1 > n - i) break;
ans = ans + A(n - i, i - 1) * tt % mod;
ans %= mod;
tt = tt * fpow(n - i, mod - 2) % mod;
}
cout << ans << '\n';
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
// cout << fixed << setprecision(1);
int T = 1;
// cin >> T;
while (T--) solve();
return 0;
}
详细
Test #1:
score: 100
Accepted
time: 89ms
memory: 159920kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 35ms
memory: 159788kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 95ms
memory: 159804kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 94ms
memory: 159804kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 74ms
memory: 159860kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 35ms
memory: 159840kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 67ms
memory: 159796kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 98ms
memory: 159760kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 85ms
memory: 159792kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 36ms
memory: 159804kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 59ms
memory: 159868kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 78ms
memory: 159920kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 63ms
memory: 159796kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 154ms
memory: 159864kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 539ms
memory: 159804kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 588ms
memory: 159828kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 460ms
memory: 159824kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 291ms
memory: 159800kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 496ms
memory: 159804kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 272ms
memory: 159800kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: 0
Accepted
time: 674ms
memory: 159856kb
input:
9999998
output:
758172780
result:
ok 1 number(s): "758172780"
Test #22:
score: 0
Accepted
time: 682ms
memory: 159860kb
input:
9999999
output:
605195495
result:
ok 1 number(s): "605195495"
Test #23:
score: 0
Accepted
time: 630ms
memory: 159796kb
input:
10000000
output:
866813682
result:
ok 1 number(s): "866813682"