QOJ.ac
QOJ
| ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
|---|---|---|---|---|---|---|---|---|---|
| #840570 | #8728. Tablica | QZJ123456 | 100 ✓ | 41ms | 74156kb | C++14 | 779b | 2025-01-02 20:16:54 | 2025-01-02 20:16:54 |
Judging History
answer
#include<bits/stdc++.h>
typedef long long ll;
using namespace std;
const ll mod=1e9+7,iv2=5e8+4;
int n,m;
ll C[3005][3005],pw[3005],fac[6005];
int main(){
cin>>n>>m;
for(int i=0;i<=3000;i++){
C[i][0]=1;
for(int j=1;j<=i;j++)C[i][j]=(C[i-1][j]+C[i-1][j-1])%mod;
}
pw[0]=fac[0]=1;
for(int i=1;i<=3000;i++)pw[i]=pw[i-1]*iv2%mod;
for(int i=1;i<=6000;i++)fac[i]=fac[i-1]*i%mod;
ll ans=0;
for(int i=0;i<=n;i++){
int s=2*i+(n-i);
int c2=s-m;
if(c2<0||c2>m)continue;
ll sum=0;
for(int j=0;j<=i&&j<=c2;j++){
ll add=C[c2][j]*C[i][j]%mod*fac[s-2*j]%mod*pw[c2-j]%mod*fac[j]%mod;
if(j&1)sum=(sum-add+mod)%mod;
else sum=(sum+add)%mod;
}
sum=sum*pw[i]%mod;
ans=(ans+sum*C[n][i]%mod*C[m][c2])%mod;
}
cout<<ans;
return 0;
}
Details
Tip: Click on the bar to expand more detailed information
Subtask #1:
score: 10
Accepted
Test #1:
score: 10
Accepted
time: 4ms
memory: 73684kb
input:
5 6
output:
456750
result:
ok 1 number(s): "456750"
Test #2:
score: 10
Accepted
time: 11ms
memory: 73988kb
input:
6 6
output:
5464710
result:
ok 1 number(s): "5464710"
Test #3:
score: 10
Accepted
time: 0ms
memory: 72608kb
input:
3 5
output:
270
result:
ok 1 number(s): "270"
Test #4:
score: 10
Accepted
time: 3ms
memory: 72852kb
input:
3 6
output:
90
result:
ok 1 number(s): "90"
Test #5:
score: 10
Accepted
time: 11ms
memory: 73992kb
input:
4 6
output:
14580
result:
ok 1 number(s): "14580"
Test #6:
score: 10
Accepted
time: 0ms
memory: 73684kb
input:
3 4
output:
270
result:
ok 1 number(s): "270"
Subtask #2:
score: 18
Accepted
Dependency #1:
100%
Accepted
Test #7:
score: 18
Accepted
time: 7ms
memory: 73404kb
input:
50 49
output:
750700714
result:
ok 1 number(s): "750700714"
Test #8:
score: 18
Accepted
time: 14ms
memory: 74000kb
input:
50 50
output:
630532893
result:
ok 1 number(s): "630532893"
Test #9:
score: 18
Accepted
time: 7ms
memory: 73032kb
input:
41 34
output:
800856205
result:
ok 1 number(s): "800856205"
Test #10:
score: 18
Accepted
time: 7ms
memory: 73696kb
input:
39 41
output:
541550932
result:
ok 1 number(s): "541550932"
Test #11:
score: 18
Accepted
time: 4ms
memory: 73396kb
input:
38 46
output:
651393374
result:
ok 1 number(s): "651393374"
Test #12:
score: 18
Accepted
time: 3ms
memory: 72764kb
input:
37 39
output:
746919932
result:
ok 1 number(s): "746919932"
Test #13:
score: 18
Accepted
time: 7ms
memory: 72616kb
input:
30 50
output:
214086425
result:
ok 1 number(s): "214086425"
Test #14:
score: 18
Accepted
time: 3ms
memory: 72632kb
input:
50 41
output:
193351204
result:
ok 1 number(s): "193351204"
Test #15:
score: 18
Accepted
time: 11ms
memory: 73076kb
input:
44 32
output:
63855946
result:
ok 1 number(s): "63855946"
Test #16:
score: 18
Accepted
time: 11ms
memory: 74156kb
input:
45 42
output:
266239299
result:
ok 1 number(s): "266239299"
Subtask #3:
score: 31
Accepted
Dependency #1:
100%
Accepted
Dependency #2:
100%
Accepted
Test #17:
score: 31
Accepted
time: 4ms
memory: 73724kb
input:
199 200
output:
841552647
result:
ok 1 number(s): "841552647"
Test #18:
score: 31
Accepted
time: 15ms
memory: 73244kb
input:
200 200
output:
157842226
result:
ok 1 number(s): "157842226"
Test #19:
score: 31
Accepted
time: 7ms
memory: 73984kb
input:
156 199
output:
216453917
result:
ok 1 number(s): "216453917"
Test #20:
score: 31
Accepted
time: 14ms
memory: 73972kb
input:
161 199
output:
539960909
result:
ok 1 number(s): "539960909"
Test #21:
score: 31
Accepted
time: 7ms
memory: 73256kb
input:
194 160
output:
764024671
result:
ok 1 number(s): "764024671"
Test #22:
score: 31
Accepted
time: 3ms
memory: 73548kb
input:
184 195
output:
117763744
result:
ok 1 number(s): "117763744"
Test #23:
score: 31
Accepted
time: 7ms
memory: 73888kb
input:
152 174
output:
350941677
result:
ok 1 number(s): "350941677"
Test #24:
score: 31
Accepted
time: 0ms
memory: 73844kb
input:
195 186
output:
130526660
result:
ok 1 number(s): "130526660"
Test #25:
score: 31
Accepted
time: 0ms
memory: 74084kb
input:
173 159
output:
754934766
result:
ok 1 number(s): "754934766"
Test #26:
score: 31
Accepted
time: 4ms
memory: 72896kb
input:
194 170
output:
956364877
result:
ok 1 number(s): "956364877"
Subtask #4:
score: 41
Accepted
Dependency #1:
100%
Accepted
Dependency #2:
100%
Accepted
Dependency #3:
100%
Accepted
Test #27:
score: 41
Accepted
time: 37ms
memory: 72828kb
input:
3000 2999
output:
5195706
result:
ok 1 number(s): "5195706"
Test #28:
score: 41
Accepted
time: 40ms
memory: 73548kb
input:
3000 3000
output:
224347336
result:
ok 1 number(s): "224347336"
Test #29:
score: 41
Accepted
time: 37ms
memory: 73912kb
input:
2854 2864
output:
513408195
result:
ok 1 number(s): "513408195"
Test #30:
score: 41
Accepted
time: 32ms
memory: 72552kb
input:
2887 2803
output:
58832696
result:
ok 1 number(s): "58832696"
Test #31:
score: 41
Accepted
time: 34ms
memory: 73188kb
input:
2800 2925
output:
804387597
result:
ok 1 number(s): "804387597"
Test #32:
score: 41
Accepted
time: 28ms
memory: 73048kb
input:
2842 2813
output:
971828715
result:
ok 1 number(s): "971828715"
Test #33:
score: 41
Accepted
time: 34ms
memory: 73916kb
input:
2808 2972
output:
329457042
result:
ok 1 number(s): "329457042"
Test #34:
score: 41
Accepted
time: 36ms
memory: 73184kb
input:
2821 2853
output:
81282690
result:
ok 1 number(s): "81282690"
Test #35:
score: 41
Accepted
time: 36ms
memory: 74012kb
input:
2875 2956
output:
105351485
result:
ok 1 number(s): "105351485"
Test #36:
score: 41
Accepted
time: 41ms
memory: 72704kb
input:
2879 2852
output:
672034506
result:
ok 1 number(s): "672034506"
Extra Test:
score: 0
Extra Test Passed