QOJ.ac
QOJ
| ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
|---|---|---|---|---|---|---|---|---|---|
| #637992 | #8339. Rooted Tree | Layn# | AC ✓ | 164ms | 238272kb | C++14 | 818b | 2024-10-13 14:34:32 | 2024-10-13 14:34:35 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
const int N=1e7+4,mod=1000000009;
int n,m,a[N],pre[N],suf[N],inv[N],f[N],g[N];
int mul(int x,int y){return 1ll*x*y%mod;}
int add(int x,int y) {
int z=x+y;
if(z<mod)return z;
return z-mod;
}
int qpow(int x,int y,int res=1) {
for(int cur=x;y;y>>=1,cur=mul(cur,cur))if(y&1)res=mul(res,cur);
return res;
}
int main() {
scanf("%d%d",&m,&n);
for(int i=1;i<=n;i++)a[i]=i*m-i+1;
pre[0]=1,suf[n+1]=1;
for(int i=1;i<=n;i++)pre[i]=mul(pre[i-1],a[i]);
for(int i=n;i>=1;i--)suf[i]=mul(suf[i+1],a[i]);
int INV=qpow(pre[n],mod-2);
for(int i=1;i<=n;i++)inv[i]=mul(mul(pre[i-1],suf[i+1]),INV);
for(int i=1;i<=n;i++)
g[i]=add(g[i-1],mul(m,inv[i])),f[i]=add(f[i-1],mul(g[i-1]+1,m));
printf("%d",f[n]);
}
Details
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Test #1:
score: 100
Accepted
time: 2ms
memory: 12092kb
input:
6 2
output:
18
result:
ok 1 number(s): "18"
Test #2:
score: 0
Accepted
time: 0ms
memory: 12144kb
input:
2 6
output:
600000038
result:
ok 1 number(s): "600000038"
Test #3:
score: 0
Accepted
time: 7ms
memory: 30044kb
input:
83 613210
output:
424200026
result:
ok 1 number(s): "424200026"
Test #4:
score: 0
Accepted
time: 102ms
memory: 170824kb
input:
48 6713156
output:
198541581
result:
ok 1 number(s): "198541581"
Test #5:
score: 0
Accepted
time: 0ms
memory: 11904kb
input:
1 111
output:
6216
result:
ok 1 number(s): "6216"
Test #6:
score: 0
Accepted
time: 104ms
memory: 187580kb
input:
28 7304152
output:
457266679
result:
ok 1 number(s): "457266679"
Test #7:
score: 0
Accepted
time: 62ms
memory: 112160kb
input:
38 4101162
output:
232117382
result:
ok 1 number(s): "232117382"
Test #8:
score: 0
Accepted
time: 155ms
memory: 237608kb
input:
51 9921154
output:
340670552
result:
ok 1 number(s): "340670552"
Test #9:
score: 0
Accepted
time: 29ms
memory: 62792kb
input:
79 1801157
output:
620550406
result:
ok 1 number(s): "620550406"
Test #10:
score: 0
Accepted
time: 63ms
memory: 141216kb
input:
22 5417157
output:
457449071
result:
ok 1 number(s): "457449071"
Test #11:
score: 0
Accepted
time: 55ms
memory: 87576kb
input:
25 3210162
output:
36368303
result:
ok 1 number(s): "36368303"
Test #12:
score: 0
Accepted
time: 48ms
memory: 87684kb
input:
67 2919160
output:
935195555
result:
ok 1 number(s): "935195555"
Test #13:
score: 0
Accepted
time: 144ms
memory: 215464kb
input:
77 8613163
output:
482832472
result:
ok 1 number(s): "482832472"
Test #14:
score: 0
Accepted
time: 153ms
memory: 238216kb
input:
90 10000000
output:
275581651
result:
ok 1 number(s): "275581651"
Test #15:
score: 0
Accepted
time: 142ms
memory: 238272kb
input:
99 9999999
output:
126087169
result:
ok 1 number(s): "126087169"
Test #16:
score: 0
Accepted
time: 164ms
memory: 238072kb
input:
100 10000000
output:
451590067
result:
ok 1 number(s): "451590067"
Extra Test:
score: 0
Extra Test Passed