QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#676733 | #8339. Rooted Tree | ItzDesert | AC ✓ | 253ms | 316216kb | C++17 | 1.5kb | 2024-10-25 23:47:05 | 2024-10-25 23:47:05 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const ll p = 1e9+9;
ll qpow(ll a,ll n)
{
ll ans = 1;
while(n)
{
if(n&1) ans = (ans*a)%p;
a = (a*a)%p;
n>>=1;
}
return ans;
}
const int maxn = 1e7+5;
ll s[maxn],sv[maxn],inv[maxn];
ll E2[maxn];
void mod(ll & x)
{
if(x>=p) x-=p;
else if(x<0) x+=p;
}
//(m-1)(x-1)+1 for x = 1 到 k.
void init(int m,int k)
{
s[0] = 1;
for(int i = 1;i<=k;i++)
{
ll curval = 1ll*(m-1)*(i-1)+1;
s[i] = (s[i-1]*curval)%p;
}
sv[k] = qpow(s[k],p-2);
for(int i = k;i>=1;i--)
{
ll curval = 1ll*(m-1)*(i-1)+1;
sv[i-1] = (sv[i]*curval)%p;
}
for(int i = 1;i<=k;i++) inv[i] = (sv[i]*s[i-1])%p;
//i次操作后的叶子深度和期望
E2[0] = 0;
for(int i = 1;i<=k;i++)
{
E2[i] = (1ll*(m-1)*i+1)*inv[i]%p*E2[i-1]%p;
E2[i]+=m;
mod(E2[i]);
}
ll ans = 0;
//每次操作的贡献:上一次操作后的叶子深度和预期 / 叶子数目 = avg深度
for(int i = 1;i<=k;i++)
{
ll del = E2[i-1]*inv[i]%p;
del++;mod(del);
del = (del*m)%p;
ans+=del;
mod(ans);
}
cout<<ans<<'\n';
}
void solve()
{
int m,k;cin>>m>>k;
init(m,k);
for(int i = 1;i<=k;i++)
{
}
}
int main(){
ios::sync_with_stdio(false);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: 0ms
memory: 9852kb
input:
6 2
output:
18
result:
ok 1 number(s): "18"
Test #2:
score: 0
Accepted
time: 1ms
memory: 9808kb
input:
2 6
output:
600000038
result:
ok 1 number(s): "600000038"
Test #3:
score: 0
Accepted
time: 16ms
memory: 31440kb
input:
83 613210
output:
424200026
result:
ok 1 number(s): "424200026"
Test #4:
score: 0
Accepted
time: 160ms
memory: 218696kb
input:
48 6713156
output:
198541581
result:
ok 1 number(s): "198541581"
Test #5:
score: 0
Accepted
time: 1ms
memory: 9788kb
input:
1 111
output:
6216
result:
ok 1 number(s): "6216"
Test #6:
score: 0
Accepted
time: 184ms
memory: 240352kb
input:
28 7304152
output:
457266679
result:
ok 1 number(s): "457266679"
Test #7:
score: 0
Accepted
time: 100ms
memory: 142044kb
input:
38 4101162
output:
232117382
result:
ok 1 number(s): "232117382"
Test #8:
score: 0
Accepted
time: 246ms
memory: 315472kb
input:
51 9921154
output:
340670552
result:
ok 1 number(s): "340670552"
Test #9:
score: 0
Accepted
time: 40ms
memory: 68460kb
input:
79 1801157
output:
620550406
result:
ok 1 number(s): "620550406"
Test #10:
score: 0
Accepted
time: 137ms
memory: 177804kb
input:
22 5417157
output:
457449071
result:
ok 1 number(s): "457449071"
Test #11:
score: 0
Accepted
time: 93ms
memory: 110976kb
input:
25 3210162
output:
36368303
result:
ok 1 number(s): "36368303"
Test #12:
score: 0
Accepted
time: 76ms
memory: 101376kb
input:
67 2919160
output:
935195555
result:
ok 1 number(s): "935195555"
Test #13:
score: 0
Accepted
time: 220ms
memory: 278864kb
input:
77 8613163
output:
482832472
result:
ok 1 number(s): "482832472"
Test #14:
score: 0
Accepted
time: 241ms
memory: 316216kb
input:
90 10000000
output:
275581651
result:
ok 1 number(s): "275581651"
Test #15:
score: 0
Accepted
time: 253ms
memory: 316140kb
input:
99 9999999
output:
126087169
result:
ok 1 number(s): "126087169"
Test #16:
score: 0
Accepted
time: 244ms
memory: 316164kb
input:
100 10000000
output:
451590067
result:
ok 1 number(s): "451590067"
Extra Test:
score: 0
Extra Test Passed