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 |
---|---|---|---|---|---|---|---|---|---|
#132647 | #6736. Alice and Bob | bucketpotato# | AC ✓ | 596ms | 42696kb | C++20 | 933b | 2023-07-30 22:58:35 | 2023-07-30 22:58:36 |
Judging History
answer
#include "bits/stdc++.h"
using namespace std;
#define ll long long
const ll MOD = 998244353;
const int MAXN = 10000010;
int f[MAXN];
ll binexp(ll x, ll y) {
ll mu = 1;
while (y > 0) {
if (y % 2) {
mu *= x;
mu %= MOD;
y--;
}
else {
x *= x;
x %= MOD;
y /= 2;
}
}
return mu;
}
int main() {
cin.tie(0)->sync_with_stdio(0);
cin.exceptions(cin.failbit);
int n; cin >> n;
f[0] = 1;
for (int i = 1; i < MAXN; i++) {
f[i] = (((ll)f[i - 1]) * ((ll)i)) % MOD;
}
ll ans = 0;
for (ll i = 1; i <= n; i++) {
ll rm = n - i;
// need to choose (i - 1) out of rm
// then permute them arbitrarily
if (rm >= i - 1) {
ll ta = (f[rm] * binexp(f[rm - (i - 1)], MOD - 2)) % MOD;
ta *= f[rm];
ta %= MOD;
ans += ta;
ans %= MOD;
}
}
cout << ans << "\n";
}
詳細信息
Test #1:
score: 100
Accepted
time: 38ms
memory: 42436kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 41ms
memory: 42696kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 37ms
memory: 42660kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 45ms
memory: 42520kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 49ms
memory: 42536kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 49ms
memory: 42480kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 37ms
memory: 42524kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 41ms
memory: 42480kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 38ms
memory: 42524kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 36ms
memory: 42656kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 37ms
memory: 42696kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 40ms
memory: 42476kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 36ms
memory: 42520kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 116ms
memory: 42528kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 459ms
memory: 42440kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 490ms
memory: 42480kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 380ms
memory: 42528kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 234ms
memory: 42596kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 430ms
memory: 42692kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 209ms
memory: 42528kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: 0
Accepted
time: 596ms
memory: 42520kb
input:
9999998
output:
758172780
result:
ok 1 number(s): "758172780"
Test #22:
score: 0
Accepted
time: 592ms
memory: 42484kb
input:
9999999
output:
605195495
result:
ok 1 number(s): "605195495"
Test #23:
score: 0
Accepted
time: 593ms
memory: 42532kb
input:
10000000
output:
866813682
result:
ok 1 number(s): "866813682"