QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#474429 | #2568. Mountains | lichenyu_ac | AC ✓ | 15ms | 22928kb | C++14 | 1.2kb | 2024-07-12 18:05:16 | 2024-07-12 18:05:17 |
Judging History
answer
#include<bits/stdc++.h>
#define ing long long
typedef long long ll;
using namespace std;
const int N=2e3+10,M=1e6+10,mod=1e9+7;
ll power(ll a,ll b){
ll ans=1;
for(;b;b>>=1){
if(b&1)ans=ans*a%mod;
a=a*a%mod;
}
return ans;
}
ll n,m,K;
ll A[N][N],f[M],incf[M];
void init(int len){
f[0]=1;
for(int i=1;i<=len;i++)f[i]=f[i-1]*i%mod;
incf[len]=power(f[len],mod-2);
for(int i=len-1;i>=0;i--)incf[i]=incf[i+1]*(i+1)%mod;
}
ll C(ll a,ll b){
if(a<b)return 0;
return f[a]*incf[b]%mod*incf[a-b]%mod;
}
ll Guess(){
ll op=1,ans=1;
for(int i=1;i<=K;i++){
int pos=i;
for(int j=i+1;j<=K;j++)
if(A[j][i]>A[pos][i])pos=j;
if(i!=pos)op=-op,swap(A[i],A[pos]);
if(!A[i][i])return 0;
for(int j=1;j<=K;j++){
if(j==i)continue;
ll tmp=A[j][i]*power(A[i][i],mod-2)%mod;
for(int k=1;k<=K;k++)
A[j][k]=(A[j][k]-tmp*A[i][k]%mod+mod)%mod;
}
ans=ans*A[i][i]%mod;
ll tmp=power(A[i][i],mod-2);
for(int j=1;j<=K;j++)A[i][j]=A[i][j]*tmp%mod;
}
return (ans*op%mod+mod)%mod;
}
signed main(){
init(M-1);
scanf("%lld%lld%lld",&n,&m,&K);
for(int i=1;i<=K;i++)
for(int j=1;j<=K;j++){
ll x=n+(j-i),y=m-(j-i);
if(x>=0&&y>=0&&x<N&&y<N)A[i][j]=C(x+y,x);
}
printf("%lld\n",Guess());
return 0;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 8ms
memory: 21436kb
input:
1 1 1
output:
2
result:
ok 1 number(s): "2"
Test #2:
score: 0
Accepted
time: 12ms
memory: 20232kb
input:
2 2 2
output:
20
result:
ok 1 number(s): "20"
Test #3:
score: 0
Accepted
time: 7ms
memory: 20284kb
input:
2 3 4
output:
490
result:
ok 1 number(s): "490"
Test #4:
score: 0
Accepted
time: 7ms
memory: 19876kb
input:
1 2 8
output:
45
result:
ok 1 number(s): "45"
Test #5:
score: 0
Accepted
time: 7ms
memory: 21172kb
input:
1 10 2
output:
66
result:
ok 1 number(s): "66"
Test #6:
score: 0
Accepted
time: 3ms
memory: 21100kb
input:
9 5 7
output:
371850968
result:
ok 1 number(s): "371850968"
Test #7:
score: 0
Accepted
time: 7ms
memory: 20400kb
input:
3 3 1
output:
20
result:
ok 1 number(s): "20"
Test #8:
score: 0
Accepted
time: 7ms
memory: 21704kb
input:
7 7 9
output:
166345303
result:
ok 1 number(s): "166345303"
Test #9:
score: 0
Accepted
time: 11ms
memory: 20508kb
input:
25 15 25
output:
850087558
result:
ok 1 number(s): "850087558"
Test #10:
score: 0
Accepted
time: 8ms
memory: 21632kb
input:
45 59 71
output:
659153227
result:
ok 1 number(s): "659153227"
Test #11:
score: 0
Accepted
time: 11ms
memory: 21928kb
input:
73 3 25
output:
683124269
result:
ok 1 number(s): "683124269"
Test #12:
score: 0
Accepted
time: 9ms
memory: 22056kb
input:
1 48 78
output:
446896916
result:
ok 1 number(s): "446896916"
Test #13:
score: 0
Accepted
time: 7ms
memory: 21256kb
input:
25 100 32
output:
966287506
result:
ok 1 number(s): "966287506"
Test #14:
score: 0
Accepted
time: 8ms
memory: 21728kb
input:
85 64 40
output:
125679545
result:
ok 1 number(s): "125679545"
Test #15:
score: 0
Accepted
time: 7ms
memory: 21104kb
input:
5 9 94
output:
620471576
result:
ok 1 number(s): "620471576"
Test #16:
score: 0
Accepted
time: 12ms
memory: 21728kb
input:
33 57 40
output:
637315057
result:
ok 1 number(s): "637315057"
Test #17:
score: 0
Accepted
time: 10ms
memory: 22928kb
input:
61 6 97
output:
362472796
result:
ok 1 number(s): "362472796"
Test #18:
score: 0
Accepted
time: 12ms
memory: 20628kb
input:
85 50 51
output:
192099209
result:
ok 1 number(s): "192099209"
Test #19:
score: 0
Accepted
time: 12ms
memory: 21752kb
input:
96 54 59
output:
714762612
result:
ok 1 number(s): "714762612"
Test #20:
score: 0
Accepted
time: 11ms
memory: 20340kb
input:
20 99 12
output:
772155662
result:
ok 1 number(s): "772155662"
Test #21:
score: 0
Accepted
time: 6ms
memory: 22224kb
input:
48 39 62
output:
670046604
result:
ok 1 number(s): "670046604"
Test #22:
score: 0
Accepted
time: 5ms
memory: 21148kb
input:
76 83 16
output:
976820079
result:
ok 1 number(s): "976820079"
Test #23:
score: 0
Accepted
time: 4ms
memory: 22044kb
input:
96 36 61
output:
20854557
result:
ok 1 number(s): "20854557"
Test #24:
score: 0
Accepted
time: 13ms
memory: 21852kb
input:
18 40 77
output:
261684871
result:
ok 1 number(s): "261684871"
Test #25:
score: 0
Accepted
time: 12ms
memory: 20776kb
input:
42 84 26
output:
458573307
result:
ok 1 number(s): "458573307"
Test #26:
score: 0
Accepted
time: 9ms
memory: 21200kb
input:
71 25 80
output:
875902815
result:
ok 1 number(s): "875902815"
Test #27:
score: 0
Accepted
time: 7ms
memory: 20120kb
input:
95 73 26
output:
922299967
result:
ok 1 number(s): "922299967"
Test #28:
score: 0
Accepted
time: 13ms
memory: 21148kb
input:
19 17 83
output:
494148696
result:
ok 1 number(s): "494148696"
Test #29:
score: 0
Accepted
time: 15ms
memory: 22796kb
input:
100 100 100
output:
192912055
result:
ok 1 number(s): "192912055"
Test #30:
score: 0
Accepted
time: 11ms
memory: 21836kb
input:
100 98 99
output:
412293529
result:
ok 1 number(s): "412293529"