QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#383958 | #6736. Alice and Bob | GordenGhost | AC ✓ | 190ms | 159972kb | C++17 | 1.3kb | 2024-04-09 19:12:25 | 2024-04-09 19:12:25 |
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;
}
ll inverse(ll a,ll m){
return qpow(fact[a],m-2,m);
// if(a==0)
// return qpow(fact[0],m-2,m);
// return inv[a];
}
ll C(ll n,ll r,ll m){
if(r>n)
return 0;
return ((fact[n]*inverse(r,m))%m*inverse(n-r,m)%m);
}
ll Lucas(ll n,ll r,ll m){
if(r==0)
return 1;
return C(n%m,r%m,m)*Lucas(n/m,r/m,m)%m;
}
void init(ll n,ll p){
fact[0]=1;
for(int i=1;i<=n;i++)
fact[i]=(fact[i-1]*i)%p;
inv[1]=1;
for(int i=2;i<=N-5;i++){
inv[i]=(mod-mod/i)*inv[mod%i]%mod;
}
}
void slove(){
int n;
cin>>n;
init(n,mod);
ll ans=0;
if(n==1){
cout<<1<<endl;
return;
}
ll tot=1;
int j=n-1;
for(int i=1;i<=(n+1)/2;i++){
// ans+= Lucas(n-i,i-1,mod)*fact[i-1]%mod *fact[n-i]%mod;
// cout<<Lucas(n-i,i-1,mod)*fact[i-1]%mod *fact[n-i]%mod<<endl;
// ans%=mod;
for(;j>=n-2*i+2;j--){
tot*=j;
tot%=mod;
}
// cout<<tot<<endl;
ans+=tot*fact[n-i];
ans%=mod;
tot=tot*inv[n-i];
tot%=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: 68ms
memory: 83532kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 85ms
memory: 83624kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 63ms
memory: 82064kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 69ms
memory: 82068kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 70ms
memory: 83220kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 64ms
memory: 82232kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 70ms
memory: 82828kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 75ms
memory: 83536kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 74ms
memory: 82624kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 75ms
memory: 82660kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 71ms
memory: 81916kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 74ms
memory: 81780kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 68ms
memory: 82896kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 93ms
memory: 92808kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 153ms
memory: 141780kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 165ms
memory: 146716kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 161ms
memory: 130980kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 128ms
memory: 110096kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 158ms
memory: 138164kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 110ms
memory: 106124kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: 0
Accepted
time: 184ms
memory: 159896kb
input:
9999998
output:
758172780
result:
ok 1 number(s): "758172780"
Test #22:
score: 0
Accepted
time: 190ms
memory: 159972kb
input:
9999999
output:
605195495
result:
ok 1 number(s): "605195495"
Test #23:
score: 0
Accepted
time: 175ms
memory: 159904kb
input:
10000000
output:
866813682
result:
ok 1 number(s): "866813682"