QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#65847 | #4843. Infectious Disease | yezzz | AC ✓ | 2728ms | 316212kb | C++17 | 1.9kb | 2022-12-03 19:48:53 | 2022-12-03 19:48:54 |
Judging History
answer
#include<bits/stdc++.h>
#define int long long
#define endl '\n'
#define pii pair<int,int>
using namespace std;
const int mo=1e9+7, N=2e7+5;
int dp[17][400005];
int ksm(int a,int b=mo-2)
{
int res=1;
while(b)
{
if(b&1) res=res*a%mo;
a=a*a%mo; b>>=1;
}
return res;
}
int fac[N], inv[N];
void init()
{
fac[0]=inv[0]=1;
int m=2e7;
for(int i=1;i<=m;i++) fac[i]=fac[i-1]*i%mo;
inv[m]=ksm(fac[m]);
for(int i=m-1;i>=1;i--) inv[i]=inv[i+1]*(i+1)%mo;
}
int C(int n,int m)
{
if(m>n || m<0 || n<0) return 0;
return fac[n]*inv[m]%mo*inv[n-m]%mo;
}
void solve(){
init();
int n; cin>>n;
int cnt=0, t=1;
while(t<n) t*=3, cnt++;
dp[0][1]=1;
// dp[1][2]=
int mxj=1,mxc=1;
for(int i=1;i<cnt;i++)
{
mxj*=2;
for(int j=0;j<=mxj;j++)
{
int sum=n-mxc, c=2*mxc;
int tmp=ksm(C(sum,c));
for(int k=1;k<=mxj/2;k++)
{
// cout<<i<<' '<<j<<' '<<k<<" ???\n";
dp[i][j]+=dp[i-1][k]*C(2*k,j)%mo*C(sum-2*k,c-(2*k-j))%mo*tmp%mo;
dp[i][j]%=mo;
}
// cout<<i<<' '<<j<<' '<<dp[i][j]<<"\n";
}
mxc*=3;
}
int ans=0;
// cout<<dp[2][0]<<"\n";
// for(int i=1;i<=1000;i++) if(i*ksm(36)%mo==dp[2][0]) cout<<i<<"\n";
// cout<<dp[2][0]<<' '<<35*ksm(36)%mo<<"\n";
for(int i=1;i<cnt;i++) (ans+=i*dp[i][0]%mo)%=mo;
// cout<<ans<<"\n";
// cout<<39*ksm(36)%mo<<"\n";
for(int i=1;i<=ksm(2,cnt+1);i++) (ans+=cnt*dp[cnt-1][i]%mo)%=mo;
cout<<ans<<'\n';
// for(int i=1;i<=500;i++) if(i*ksm(36)%mo==ans) cout<<i<<"\n";
// cout<<ans<<"\n";
// cout<<87*ksm(36)%mo<<"\n";
}
signed main(){
ios::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
int t=1;
//cin>>t;
while(t--){
solve();
}
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 229ms
memory: 315824kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 222ms
memory: 315832kb
input:
114
output:
505208013
result:
ok 1 number(s): "505208013"
Test #3:
score: 0
Accepted
time: 2691ms
memory: 316088kb
input:
14000000
output:
44565093
result:
ok 1 number(s): "44565093"
Test #4:
score: 0
Accepted
time: 2687ms
memory: 316084kb
input:
12345678
output:
123143093
result:
ok 1 number(s): "123143093"
Test #5:
score: 0
Accepted
time: 405ms
memory: 315828kb
input:
776777
output:
764022068
result:
ok 1 number(s): "764022068"
Test #6:
score: 0
Accepted
time: 218ms
memory: 315792kb
input:
3
output:
1
result:
ok 1 number(s): "1"
Test #7:
score: 0
Accepted
time: 241ms
memory: 315832kb
input:
4
output:
666666673
result:
ok 1 number(s): "666666673"
Test #8:
score: 0
Accepted
time: 213ms
memory: 315880kb
input:
5
output:
833333341
result:
ok 1 number(s): "833333341"
Test #9:
score: 0
Accepted
time: 198ms
memory: 315780kb
input:
6
output:
300000004
result:
ok 1 number(s): "300000004"
Test #10:
score: 0
Accepted
time: 246ms
memory: 315784kb
input:
7
output:
533333339
result:
ok 1 number(s): "533333339"
Test #11:
score: 0
Accepted
time: 232ms
memory: 315908kb
input:
8
output:
952380961
result:
ok 1 number(s): "952380961"
Test #12:
score: 0
Accepted
time: 221ms
memory: 315724kb
input:
9
output:
964285723
result:
ok 1 number(s): "964285723"
Test #13:
score: 0
Accepted
time: 230ms
memory: 315828kb
input:
10
output:
416666672
result:
ok 1 number(s): "416666672"
Test #14:
score: 0
Accepted
time: 178ms
memory: 315736kb
input:
26
output:
990086590
result:
ok 1 number(s): "990086590"
Test #15:
score: 0
Accepted
time: 230ms
memory: 315800kb
input:
27
output:
528360342
result:
ok 1 number(s): "528360342"
Test #16:
score: 0
Accepted
time: 237ms
memory: 315740kb
input:
28
output:
273239648
result:
ok 1 number(s): "273239648"
Test #17:
score: 0
Accepted
time: 881ms
memory: 315964kb
input:
4782967
output:
332194401
result:
ok 1 number(s): "332194401"
Test #18:
score: 0
Accepted
time: 887ms
memory: 316016kb
input:
4782968
output:
362625027
result:
ok 1 number(s): "362625027"
Test #19:
score: 0
Accepted
time: 849ms
memory: 315972kb
input:
4782969
output:
971032452
result:
ok 1 number(s): "971032452"
Test #20:
score: 0
Accepted
time: 1572ms
memory: 316124kb
input:
4782970
output:
452836984
result:
ok 1 number(s): "452836984"
Test #21:
score: 0
Accepted
time: 1575ms
memory: 316028kb
input:
4782971
output:
349324970
result:
ok 1 number(s): "349324970"
Test #22:
score: 0
Accepted
time: 1578ms
memory: 316112kb
input:
4782972
output:
46862963
result:
ok 1 number(s): "46862963"
Test #23:
score: 0
Accepted
time: 200ms
memory: 315772kb
input:
114514
output:
972669965
result:
ok 1 number(s): "972669965"
Test #24:
score: 0
Accepted
time: 847ms
memory: 316088kb
input:
1919810
output:
482430785
result:
ok 1 number(s): "482430785"
Test #25:
score: 0
Accepted
time: 2728ms
memory: 316212kb
input:
8877877
output:
486769120
result:
ok 1 number(s): "486769120"