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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 |
---|---|---|---|---|---|---|---|---|---|
#401349 | #6736. Alice and Bob | yueboss# | TL | 921ms | 134696kb | C++14 | 987b | 2024-04-28 15:38:12 | 2024-04-28 15:38:12 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
const int N = 1e7 + 5, mod = 998244353., P = 1e9 + 9;
const int inf = 0x3f3f3f3f;
#define endl '\n'
typedef long long ll;
typedef double db;
typedef pair<int, int> pii;
int T; ll n, m;
ll fac[N], inv[N];
ll qpow(ll a, int n) {
ll res = 1;
while(n) {
if(n&1) res = res*a % mod;
a = a*a % mod;
n >>= 1;
}
return res;
}
ll C(ll n, ll m) {
return fac[n]*inv[m] % mod * inv[n-m] % mod;
}
void solve() {
cin >> n;
fac[0] = inv[0] = 1;
for(int i = 1; i <= n; i++) {
fac[i] = fac[i-1]*i % mod;
inv[i] = inv[i-1]*qpow(i, mod-2) % mod;
}
ll ans = 0;
for(int i = 1; i+i <= n+1; i++) {
ans = (ans + C(n-i, i-1)*fac[i-1] % mod* fac[n-i] % mod) % mod;
}
cout << ans << '\n';
}
int main() {
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
T = 1;
//cin >> T;
while(T--) solve();
return 0;
}
详细
Test #1:
score: 100
Accepted
time: 1ms
memory: 5772kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 1ms
memory: 5580kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 1ms
memory: 5764kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 0ms
memory: 5716kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 0ms
memory: 5716kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 0ms
memory: 5620kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 0ms
memory: 5624kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 0ms
memory: 5716kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 1ms
memory: 5688kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 1ms
memory: 5648kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 1ms
memory: 5620kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 1ms
memory: 5692kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 1ms
memory: 5632kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 155ms
memory: 28804kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 855ms
memory: 125500kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 921ms
memory: 134696kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 701ms
memory: 104716kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 401ms
memory: 62004kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 778ms
memory: 117344kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 328ms
memory: 51836kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: -100
Time Limit Exceeded
input:
9999998