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 |
---|---|---|---|---|---|---|---|---|---|
#164714 | #2908. count | int32 | 100 | 25ms | 3544kb | C++11 | 712b | 2022-11-05 15:33:52 | 2022-11-05 15:33:53 |
answer
//syc
#include<bits/stdc++.h>
using namespace std;
const int R=2e5;
const int N=2e5+10;
const int mod=1e9+7;
int T;
int n, m;
int fac[N], inv[N], invfac[N];
void init(){
inv[1]=fac[0]=invfac[0]=1;
for(int i=2;i<=R;i++)
inv[i]=1ll*(mod-mod/i)*inv[mod%i]%mod;
for(int i=1;i<=R;i++)
fac[i]=1ll*fac[i-1]*i%mod;
for(int i=1;i<=R;i++)
invfac[i]=1ll*invfac[i-1]*inv[i]%mod;
}
int calc(){
return 1ll*(1ll*(n+m)*(n+m+1)/2-
1ll*n*(n+1)/2-1ll*m*(m+1)/2-1)%mod*
fac[n+m-2]%mod*invfac[n-1]%mod*
invfac[m-1]%mod;
}
signed main(){
cin>>T;
init();
while(T--){
cin>>n>>m;
cout<<calc()<<'\n';
}
return 0;
}
详细
小提示:点击横条可展开更详细的信息
Test #1:
score: 20
Accepted
time: 5ms
memory: 3544kb
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: 5ms
memory: 3544kb
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: 5ms
memory: 3540kb
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: 5ms
memory: 3540kb
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: 5ms
memory: 3544kb
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