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QOJ
ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#475687 | #2568. Mountains | cppcppcpp3 | AC ✓ | 1ms | 3728kb | C++14 | 1.6kb | 2024-07-13 16:15:00 | 2024-07-13 16:15:00 |
Judging History
answer
#include<bits/stdc++.h>
#define pii pair<int,int>
#define fi first
#define se second
using namespace std;
const int N=105;
const int p=1e9+7;
static char buf[1000000],*p1=buf,*p2=buf;
#define getchar() p1==p2&&(p2=(p1=buf)+fread(buf,1,1000000,stdin),p1==p2)?EOF:*p1++
inline int wrd(){int x=0,f=1;char c=getchar();while(c<'0' || c>'9'){if(c=='-') f=-1;c=getchar();}while(c>='0' && c<='9') {x=(x<<3)+(x<<1)+c-48;c=getchar();}return x*f;}
inline void write(int x){static char buf[20];static int len=-1;if(x<0)putchar('-'),x=-x;do buf[++len]=x%10,x/=10;while(x);while(len>=0)putchar(buf[len--]+48);}
int n,m,k;
int fac[N*3],inv[N*3];
int qpow(int a,int b){
int as=1;
while(b){
if(b&1) as=1ll*as*a%p;
a=1ll*a*a%p,b>>=1;
}
return as;
}
void init(int n){
fac[0]=1; for(int i=1;i<=n;++i) fac[i]=1ll*fac[i-1]*i%p;
inv[n]=qpow(fac[n],p-2); for(int i=n;i;--i) inv[i-1]=1ll*inv[i]*i%p;
}
int C(int n,int m){
if(n<m || m<0) return 0;
return 1ll*fac[n]*inv[m]%p*inv[n-m]%p;
}
int a[N][N],as=1;
signed main(){
n=wrd(),m=wrd(),k=wrd(),init(n+m+k);
for(int i=0;i<k;++i){ // s[i]
for(int j=0;j<k;++j){ // t[j]
int x=m+j-i,y=n+i-j;
a[i][j]=C(x+y,x);
}
}
for(int i=0;i<k;++i){
for(int j=i;j<k;++j){
if(!a[j][i]) continue;
if(i^j) as=p-as,swap(a[i],a[j]);
break;
}
if(!a[i][i]){as=0;break;}
int iv=qpow(a[i][i],p-2);
for(int j=i+1;j<k;++j){
if(!a[j][i]) continue;
int tt=a[j][i];
for(int l=i;l<k;++l){
a[j][l]=(1ll*a[j][l]-1ll*tt*iv%p*a[i][l]%p+p)%p;
}
}
}
for(int i=0;i<k;++i) as=1ll*as*a[i][i]%p;
return write(as),0;
}
详细
Test #1:
score: 100
Accepted
time: 0ms
memory: 3504kb
input:
1 1 1
output:
2
result:
ok 1 number(s): "2"
Test #2:
score: 0
Accepted
time: 0ms
memory: 3628kb
input:
2 2 2
output:
20
result:
ok 1 number(s): "20"
Test #3:
score: 0
Accepted
time: 0ms
memory: 3704kb
input:
2 3 4
output:
490
result:
ok 1 number(s): "490"
Test #4:
score: 0
Accepted
time: 0ms
memory: 3692kb
input:
1 2 8
output:
45
result:
ok 1 number(s): "45"
Test #5:
score: 0
Accepted
time: 0ms
memory: 3508kb
input:
1 10 2
output:
66
result:
ok 1 number(s): "66"
Test #6:
score: 0
Accepted
time: 0ms
memory: 3612kb
input:
9 5 7
output:
371850968
result:
ok 1 number(s): "371850968"
Test #7:
score: 0
Accepted
time: 0ms
memory: 3540kb
input:
3 3 1
output:
20
result:
ok 1 number(s): "20"
Test #8:
score: 0
Accepted
time: 0ms
memory: 3608kb
input:
7 7 9
output:
166345303
result:
ok 1 number(s): "166345303"
Test #9:
score: 0
Accepted
time: 0ms
memory: 3688kb
input:
25 15 25
output:
850087558
result:
ok 1 number(s): "850087558"
Test #10:
score: 0
Accepted
time: 1ms
memory: 3720kb
input:
45 59 71
output:
659153227
result:
ok 1 number(s): "659153227"
Test #11:
score: 0
Accepted
time: 0ms
memory: 3624kb
input:
73 3 25
output:
683124269
result:
ok 1 number(s): "683124269"
Test #12:
score: 0
Accepted
time: 1ms
memory: 3652kb
input:
1 48 78
output:
446896916
result:
ok 1 number(s): "446896916"
Test #13:
score: 0
Accepted
time: 0ms
memory: 3712kb
input:
25 100 32
output:
966287506
result:
ok 1 number(s): "966287506"
Test #14:
score: 0
Accepted
time: 0ms
memory: 3652kb
input:
85 64 40
output:
125679545
result:
ok 1 number(s): "125679545"
Test #15:
score: 0
Accepted
time: 0ms
memory: 3656kb
input:
5 9 94
output:
620471576
result:
ok 1 number(s): "620471576"
Test #16:
score: 0
Accepted
time: 0ms
memory: 3624kb
input:
33 57 40
output:
637315057
result:
ok 1 number(s): "637315057"
Test #17:
score: 0
Accepted
time: 0ms
memory: 3644kb
input:
61 6 97
output:
362472796
result:
ok 1 number(s): "362472796"
Test #18:
score: 0
Accepted
time: 0ms
memory: 3656kb
input:
85 50 51
output:
192099209
result:
ok 1 number(s): "192099209"
Test #19:
score: 0
Accepted
time: 1ms
memory: 3568kb
input:
96 54 59
output:
714762612
result:
ok 1 number(s): "714762612"
Test #20:
score: 0
Accepted
time: 0ms
memory: 3704kb
input:
20 99 12
output:
772155662
result:
ok 1 number(s): "772155662"
Test #21:
score: 0
Accepted
time: 1ms
memory: 3512kb
input:
48 39 62
output:
670046604
result:
ok 1 number(s): "670046604"
Test #22:
score: 0
Accepted
time: 0ms
memory: 3644kb
input:
76 83 16
output:
976820079
result:
ok 1 number(s): "976820079"
Test #23:
score: 0
Accepted
time: 1ms
memory: 3536kb
input:
96 36 61
output:
20854557
result:
ok 1 number(s): "20854557"
Test #24:
score: 0
Accepted
time: 1ms
memory: 3576kb
input:
18 40 77
output:
261684871
result:
ok 1 number(s): "261684871"
Test #25:
score: 0
Accepted
time: 0ms
memory: 3620kb
input:
42 84 26
output:
458573307
result:
ok 1 number(s): "458573307"
Test #26:
score: 0
Accepted
time: 1ms
memory: 3544kb
input:
71 25 80
output:
875902815
result:
ok 1 number(s): "875902815"
Test #27:
score: 0
Accepted
time: 0ms
memory: 3632kb
input:
95 73 26
output:
922299967
result:
ok 1 number(s): "922299967"
Test #28:
score: 0
Accepted
time: 1ms
memory: 3728kb
input:
19 17 83
output:
494148696
result:
ok 1 number(s): "494148696"
Test #29:
score: 0
Accepted
time: 1ms
memory: 3700kb
input:
100 100 100
output:
192912055
result:
ok 1 number(s): "192912055"
Test #30:
score: 0
Accepted
time: 1ms
memory: 3648kb
input:
100 98 99
output:
412293529
result:
ok 1 number(s): "412293529"