| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 19944 |
2016-02-25T07:43:31 Z |
tonyjjw |
순열 (kriii4_T) |
C++14 |
|
472 ms |
40784 KB |
#include <algorithm>
#include <assert.h>
#include <complex>
#include <ctype.h>
#include <functional>
#include <iostream>
#include <limits.h>
#include <locale.h>
#include <map>
#include <math.h>
#include <queue>
#include <set>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <vector>
#include <unordered_set>
#include <unordered_map>
#pragma warning(disable:4996)
using namespace std;
#define mp make_pair
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef long double ldb;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
typedef pair <ll, int> pli;
typedef pair <ldb, ldb> pdd;
int IT_MAX = 131072;
const ll MOD = 1000000007;
const int INF = 1034567891;
const ll LL_INF = 2234567890123456789ll;
const db PI = 3.141592653589793238;
const ldb ERR = 1E-10;
ll mul_inv(ll a, ll b)
{
ll b0 = b, t, q;
ll x0 = 0, x1 = 1;
if (b == 1) return 1;
while (a > 1) {
q = a / b;
t = b, b = a % b, a = t;
t = x0, x0 = x1 - q * x0, x1 = t;
}
if (x1 < 0) x1 += b0;
return x1;
}
ll F[1000050];
ll Finv[1000050];
ll dp1[1000050];
ll dp2[1000050];
ll dp3[1000050];
inline ll Comb(int x, int y) {
ll rv = F[x];
rv = (rv * Finv[y]) % MOD;
rv = (rv * Finv[x - y]) % MOD;
return rv;
}
int main() {
int N, L, K, i;
F[0] = 1;
for (i = 1; i <= 1000010; i++) F[i] = (F[i - 1] * i) % MOD;
for (i = 0; i <= 1000010; i++) Finv[i] = mul_inv(F[i], MOD);
scanf("%d %d", &N, &K);
K++;
if (K == N + 1) return !printf("0\n");
ll ans = Comb(N - K + 2, 2) * N % MOD;
ans -= 2 * Comb(N - K + 2, 3);
ans = (ans + 2 * MOD) % MOD;
ans = (ans*N) % MOD;
ans = (ans*F[N - 1]) % MOD;
for (L = K; L < N; L++) {
dp1[L] = Comb(N + 1, L + 1) * L % MOD;
dp2[L] = Comb(N + 2, L + 2);
dp2[L] = dp2[L] * L % MOD * (L + 1) % MOD;
dp2[L] = (dp2[L] - dp1[L] + MOD) % MOD;
dp3[L] = Comb(N + 3, L + 3) * L % MOD;
dp3[L] = dp3[L] * (L + 1) % MOD * (L + 2) % MOD;
dp3[L] = (dp3[L] - 3 * dp2[L] + 3 * MOD) % MOD;
dp3[L] = (dp3[L] - 2 * dp1[L] + 2 * MOD) % MOD;
ll t = Comb(L - K + 2, 2)*L%MOD;
t -= 2 * Comb(L - K + 2, 3);
t = (t + 2 * MOD) % MOD;
t = (t * F[N - L - 1]) % MOD;
t = (t * F[L-1]) % MOD;
ll t2 = 0;
t2 += (2 * N * dp1[L]) % MOD;
t2 -= 2 * dp2[L];
t2 += N*(N - 1) % MOD*dp1[L] % MOD;
t2 -= (2 * N - 1) * dp2[L] % MOD;
t2 += dp3[L];
t2 = (t2 + 100 * MOD) % MOD;
ans += (t*t2) % MOD;
}
ans = ans % MOD;
ll sum = 0;
for (i = 1; i + K - 1 <= N; i++) sum += (N - i - K + 2);
sum %= MOD;
sum *= N + 1;
sum %= MOD;
sum = (sum * F[N]) % MOD;
ans = sum - ans;
ans %= MOD;
ans += MOD;
ans %= MOD;
printf("%lld\n", ans);
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
378 ms |
40784 KB |
Output is correct |
| 2 |
Correct |
378 ms |
40784 KB |
Output is correct |
| 3 |
Correct |
378 ms |
40784 KB |
Output is correct |
| 4 |
Correct |
371 ms |
40784 KB |
Output is correct |
| 5 |
Correct |
378 ms |
40784 KB |
Output is correct |
| 6 |
Correct |
378 ms |
40784 KB |
Output is correct |
| 7 |
Correct |
378 ms |
40784 KB |
Output is correct |
| 8 |
Correct |
377 ms |
40784 KB |
Output is correct |
| 9 |
Correct |
374 ms |
40784 KB |
Output is correct |
| 10 |
Correct |
374 ms |
40784 KB |
Output is correct |
| 11 |
Correct |
378 ms |
40784 KB |
Output is correct |
| 12 |
Correct |
379 ms |
40784 KB |
Output is correct |
| 13 |
Correct |
378 ms |
40784 KB |
Output is correct |
| 14 |
Correct |
379 ms |
40784 KB |
Output is correct |
| 15 |
Correct |
376 ms |
40784 KB |
Output is correct |
| 16 |
Correct |
379 ms |
40784 KB |
Output is correct |
| 17 |
Correct |
379 ms |
40784 KB |
Output is correct |
| 18 |
Correct |
379 ms |
40784 KB |
Output is correct |
| 19 |
Correct |
375 ms |
40784 KB |
Output is correct |
| 20 |
Correct |
378 ms |
40784 KB |
Output is correct |
| 21 |
Correct |
379 ms |
40784 KB |
Output is correct |
| 22 |
Correct |
375 ms |
40784 KB |
Output is correct |
| 23 |
Correct |
379 ms |
40784 KB |
Output is correct |
| 24 |
Correct |
375 ms |
40784 KB |
Output is correct |
| 25 |
Correct |
380 ms |
40784 KB |
Output is correct |
| 26 |
Correct |
378 ms |
40784 KB |
Output is correct |
| 27 |
Correct |
375 ms |
40784 KB |
Output is correct |
| 28 |
Correct |
377 ms |
40784 KB |
Output is correct |
| 29 |
Correct |
371 ms |
40784 KB |
Output is correct |
| 30 |
Correct |
378 ms |
40784 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
472 ms |
40784 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
