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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 |
---|---|---|---|---|---|---|---|---|---|
#129386 | #6736. Alice and Bob | Seventeen_17 | AC ✓ | 230ms | 159884kb | C++17 | 1.3kb | 2023-07-22 17:50:07 | 2023-07-22 17:50:07 |
Judging History
answer
#include <bits/stdc++.h>
#define endl "\n"
#define int long long
using namespace std;
const int N = 1e7 + 10, mod = 998244353;
int f[N], vf[N]; //存储阶乘和阶乘的逆元
int ksm(int x, int y) {
int ans = 1;
while (y) {
if(y & 1) ans = ans * x % mod;
y >>= 1;
x = x * x % mod;
}
return ans % mod;
}
int inv(int x) {
return ksm(x, mod - 2) % mod;
}
void fac()
{
f[0] = vf[0] = 1;
f[1] = vf[1] = 1;
for (int i = 1; i < N; i++)
{
f[i] = (f[i - 1] % mod * i % mod) % mod;
}
for (int i = 2; i < N; i++) {
vf[i] = (mod - mod / i) * vf[mod % i] % mod;
}
for (int i = 2; i < N; i++) {
vf[i] = vf[i - 1] * vf[i] % mod;
}
}
int C(int n, int m) {
return (f[n] % mod * vf[m] % mod * vf[n - m] % mod) % mod;
}
void solve() {
int n;
cin >> n;
int ans = 0;
for (int i = 1; i <= (n + 1) / 2 ; i++) {
ans = (ans % mod + C(n - i, i - 1) % mod * f[i - 1] % mod* f[n - i] % mod) % mod;
}
cout << ans << "\n";
}
signed main()
{
ios::sync_with_stdio(false);
cin.tie(0), cout.tie(0);
fac();
int T = 1;
// cin >> T;
while (T--)
{
solve();
}
return 0;
}
详细
Test #1:
score: 100
Accepted
time: 191ms
memory: 159708kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 177ms
memory: 159736kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 192ms
memory: 159708kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 174ms
memory: 159668kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 184ms
memory: 159780kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 161ms
memory: 159672kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 180ms
memory: 159668kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 177ms
memory: 159676kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 197ms
memory: 159844kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 172ms
memory: 159876kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 199ms
memory: 159712kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 200ms
memory: 159736kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 178ms
memory: 159736kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 172ms
memory: 159624kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 200ms
memory: 159844kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 230ms
memory: 159664kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 197ms
memory: 159712kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 193ms
memory: 159708kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 212ms
memory: 159708kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 206ms
memory: 159884kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: 0
Accepted
time: 216ms
memory: 159668kb
input:
9999998
output:
758172780
result:
ok 1 number(s): "758172780"
Test #22:
score: 0
Accepted
time: 208ms
memory: 159716kb
input:
9999999
output:
605195495
result:
ok 1 number(s): "605195495"
Test #23:
score: 0
Accepted
time: 228ms
memory: 159720kb
input:
10000000
output:
866813682
result:
ok 1 number(s): "866813682"