#include<stdio.h>
#include<memory.h>
#define mod 1000000007
#define inv(a) exp(a,mod-2)
typedef long long lld;
lld exp(lld a, lld b){
if(b==0)return 1;
lld k=exp(a, b/2);
k=(k*k)%mod;
if(b%2)k=(k*a)%mod;
return k;
}
lld fac[1001001], rfac[1001001];
void init(){
lld i;
fac[0]=rfac[0]=1;
for(i=1; i<=1000001; i++){
fac[i]=(fac[i-1]*i)%mod;
rfac[i]=inv(fac[i]);
}
}
lld comb(lld a, lld b){
return fac[a]*rfac[b]%mod*rfac[a-b]%mod;
}
lld n, k, sum;
int main(){
lld i;
init();
scanf("%lld%lld", &n, &k);
for(i=k+1; i<=n; i++){
lld im = fac[n+1]*(n-i+1)%mod * inv(i+1);
im = (im%mod+mod)%mod;
sum += im, sum%=mod;
}
printf("%lld", sum);
return 0;
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
412 ms |
16724 KB |
Output is correct |
| 2 |
Correct |
409 ms |
16724 KB |
Output is correct |
| 3 |
Correct |
410 ms |
16724 KB |
Output is correct |
| 4 |
Correct |
406 ms |
16724 KB |
Output is correct |
| 5 |
Correct |
410 ms |
16724 KB |
Output is correct |
| 6 |
Correct |
409 ms |
16724 KB |
Output is correct |
| 7 |
Correct |
402 ms |
16724 KB |
Output is correct |
| 8 |
Correct |
406 ms |
16724 KB |
Output is correct |
| 9 |
Correct |
410 ms |
16724 KB |
Output is correct |
| 10 |
Correct |
411 ms |
16724 KB |
Output is correct |
| 11 |
Correct |
410 ms |
16724 KB |
Output is correct |
| 12 |
Correct |
409 ms |
16724 KB |
Output is correct |
| 13 |
Correct |
405 ms |
16724 KB |
Output is correct |
| 14 |
Correct |
402 ms |
16724 KB |
Output is correct |
| 15 |
Correct |
406 ms |
16724 KB |
Output is correct |
| 16 |
Correct |
406 ms |
16724 KB |
Output is correct |
| 17 |
Correct |
411 ms |
16724 KB |
Output is correct |
| 18 |
Correct |
411 ms |
16724 KB |
Output is correct |
| 19 |
Correct |
407 ms |
16724 KB |
Output is correct |
| 20 |
Correct |
406 ms |
16724 KB |
Output is correct |
| 21 |
Correct |
411 ms |
16724 KB |
Output is correct |
| 22 |
Correct |
411 ms |
16724 KB |
Output is correct |
| 23 |
Correct |
410 ms |
16724 KB |
Output is correct |
| 24 |
Correct |
411 ms |
16724 KB |
Output is correct |
| 25 |
Correct |
411 ms |
16724 KB |
Output is correct |
| 26 |
Correct |
411 ms |
16724 KB |
Output is correct |
| 27 |
Correct |
406 ms |
16724 KB |
Output is correct |
| 28 |
Correct |
407 ms |
16724 KB |
Output is correct |
| 29 |
Correct |
411 ms |
16724 KB |
Output is correct |
| 30 |
Correct |
407 ms |
16724 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
776 ms |
16724 KB |
Output is correct |
| 2 |
Correct |
526 ms |
16724 KB |
Output is correct |
| 3 |
Correct |
455 ms |
16724 KB |
Output is correct |
| 4 |
Correct |
438 ms |
16724 KB |
Output is correct |
| 5 |
Correct |
458 ms |
16724 KB |
Output is correct |
| 6 |
Correct |
442 ms |
16724 KB |
Output is correct |
| 7 |
Correct |
702 ms |
16724 KB |
Output is correct |
| 8 |
Correct |
586 ms |
16724 KB |
Output is correct |
| 9 |
Correct |
470 ms |
16724 KB |
Output is correct |
| 10 |
Correct |
415 ms |
16724 KB |
Output is correct |
| 11 |
Correct |
528 ms |
16724 KB |
Output is correct |
| 12 |
Correct |
411 ms |
16724 KB |
Output is correct |
| 13 |
Correct |
460 ms |
16724 KB |
Output is correct |
| 14 |
Correct |
663 ms |
16724 KB |
Output is correct |
| 15 |
Correct |
556 ms |
16724 KB |
Output is correct |
| 16 |
Correct |
644 ms |
16724 KB |
Output is correct |
| 17 |
Correct |
513 ms |
16724 KB |
Output is correct |
| 18 |
Correct |
512 ms |
16724 KB |
Output is correct |
| 19 |
Correct |
432 ms |
16724 KB |
Output is correct |
| 20 |
Correct |
536 ms |
16724 KB |
Output is correct |
| 21 |
Correct |
495 ms |
16724 KB |
Output is correct |
| 22 |
Correct |
624 ms |
16724 KB |
Output is correct |
| 23 |
Correct |
486 ms |
16724 KB |
Output is correct |
| 24 |
Correct |
452 ms |
16724 KB |
Output is correct |
| 25 |
Correct |
454 ms |
16724 KB |
Output is correct |
| 26 |
Correct |
563 ms |
16724 KB |
Output is correct |
| 27 |
Correct |
420 ms |
16724 KB |
Output is correct |
| 28 |
Correct |
408 ms |
16724 KB |
Output is correct |
| 29 |
Correct |
821 ms |
16724 KB |
Output is correct |
| 30 |
Correct |
818 ms |
16724 KB |
Output is correct |
