QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#383951 | #6736. Alice and Bob | GordenGhost | AC ✓ | 142ms | 159968kb | C++17 | 1013b | 2024-04-09 19:10:01 | 2024-04-09 19:10:01 |
Judging History
answer
#include"bits/stdc++.h"
#define endl '\n'
using ll=long long;
using namespace std;
constexpr int N=10000000+5,mod=998244353;
ll fact[N],inv[N];
ll qpow(ll a,ll b,ll p){
a%=p;
ll ans=1%p;
for(;b;b>>=1){
if(b&1)
ans=ans*a%p;
a=a*a%p;
}
return ans;
}
void init(){
fact[0]=1;
inv[0]=1;
for(int i=1;i<N;i++)
fact[i]=(i*fact[i-1])%mod;
inv[10000000]=qpow(fact[10000000],mod-2,mod);
for(int i=10000000-1;i>=1;i--){
inv[i]=inv[i+1]*(i+1)%mod;
}
// for(int i=1;i<N;i++)
// inv[i]=qpow(fact[i],mod-2,mod);
}
ll C(ll n,ll r){
if(r>n||r<0)
return 0;
if(n==r||r==0)
return 1;
return (fact[n]*inv[r]%mod*inv[n-r]%mod);
}
void slove(){
init();
int n;
cin>>n;
ll ans=0;
if(n==1){
cout<<1<<endl;
return;
}
for(int i=1;i<=(n+1)/2;i++){
ans+=C(n-i,i-1)*fact[i-1]%mod*fact[n-i]%mod;
ans%=mod;
}
cout<<ans<<endl;
}
signed main(){
cin.tie(nullptr)->sync_with_stdio(0);
int _=1;
// cin>>_;
while(_--){
slove();
}
return 0;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 70ms
memory: 159956kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 63ms
memory: 159832kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 77ms
memory: 159900kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 82ms
memory: 159836kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 86ms
memory: 159916kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 79ms
memory: 159952kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 48ms
memory: 159880kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 99ms
memory: 159952kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 89ms
memory: 159912kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 90ms
memory: 159880kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 70ms
memory: 159880kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 55ms
memory: 159964kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 48ms
memory: 159896kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 89ms
memory: 159968kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 79ms
memory: 159912kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 67ms
memory: 159896kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 77ms
memory: 159900kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 72ms
memory: 159888kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 107ms
memory: 159816kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 102ms
memory: 159836kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: 0
Accepted
time: 111ms
memory: 159936kb
input:
9999998
output:
758172780
result:
ok 1 number(s): "758172780"
Test #22:
score: 0
Accepted
time: 107ms
memory: 159892kb
input:
9999999
output:
605195495
result:
ok 1 number(s): "605195495"
Test #23:
score: 0
Accepted
time: 142ms
memory: 159920kb
input:
10000000
output:
866813682
result:
ok 1 number(s): "866813682"