ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#164600 | #2908. count | BlahDuckling747 | 100 | 42ms | 2812kb | C++11 | 1.1kb | 2022-11-05 09:59:36 | 2022-11-05 13:01:35 |
answer
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int mod=1e9+7;
const int precLen=200000;
ll qpow(ll a,ll n){
ll res=1;
while(n){
if(n&1)res=res*a%mod;
a=a*a%mod;
n>>=1;
}
return res;
}
int fact[precLen+5],finv[precLen+5];
ll binom(int n,int r){
return (ll)fact[n]*finv[n-r]%mod*finv[r]%mod;
}
void initialization(){
fact[0]=1;
for(int i=1;i<=precLen;i++){
fact[i]=(ll)fact[i-1]*i%mod;
}
finv[precLen]=qpow(fact[precLen],mod-2);
for(int i=precLen-1;i>=0;i--){
finv[i]=(ll)finv[i+1]*(i+1)%mod;
}
}
void mian(){
int n,m,ans=0,row=0,col=0;
cin>>n>>m;
n--;m--;
for(int i=0;i<n;i++)col=(col+binom(m+i,i))%mod;
for(int j=0;j<m;j++)row=(row+binom(n+j,j))%mod;
for(int i=0;i<=n;i++)ans=(ans+(i+1ll)*row)%mod;
for(int j=0;j<=m;j++)ans=(ans+(j+1ll)*col)%mod;
cout<<ans<<'\n';
}
int main(){
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
initialization();
int T;
cin>>T;
while(T--)mian();
return 0;
}
Details
小提示:点击横条可展开更详细的信息
Test #1:
score: 20
Accepted
time: 4ms
memory: 2808kb
input:
10 1 1 2000 1997 117 1647 392 452 959 1883 1046 1627 1398 1124 1372 306 1799 1007 111 1765
output:
0 57631948 737963048 807538931 137760374 398194748 77480423 174938019 583393917 445670336
result:
ok 10 lines
Test #2:
score: 20
Accepted
time: 4ms
memory: 2812kb
input:
10 1 1 2000 1997 1218 1479 350 1244 784 1715 999 92 396 1393 1726 1511 624 756 900 317
output:
0 57631948 610566455 356523655 593949258 665757514 349394180 73375269 50652564 663822508
result:
ok 10 lines
Test #3:
score: 20
Accepted
time: 12ms
memory: 2808kb
input:
10 1 1 100000 99997 36934 50467 5497 37576 83775 15544 23817 68917 33052 49207 59924 39340 2708 2614...
output:
0 73866797 788834869 539491921 582239610 497376436 343937059 324406513 13225836 35059446
result:
ok 10 lines
Test #4:
score: 20
Accepted
time: 8ms
memory: 2812kb
input:
10 1 1 100000 99997 6792 14252 90281 65716 46434 67120 18977 30384 16191 33996 3425 10433 31783 4263...
output:
0 73866797 609230597 213203975 638117274 527713366 525065128 867713025 174019248 375031322
result:
ok 10 lines
Test #5:
score: 20
Accepted
time: 14ms
memory: 2812kb
input:
10 1 1 100000 99994 47270 99792 93093 92620 88764 20724 48143 99711 33293 89038 2816 16811 97638 670...
output:
0 796648553 5720713 279796657 802039459 22848874 23038351 610731858 629891152 812026839
result:
ok 10 lines