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답안 #127489

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
127489 2019-07-09T12:44:05 Z RockyB Tents (JOI18_tents) C++17
100 / 100
 251 ms 35576 KB 
#include <bits/stdc++.h>

#define rep(a, b, c) for (int a = (b); (a) <= (c); a++)
#define per(a, b, c) for (int a = (b); (a) >= (c); a--)

#define nl '\n'
#define ioi exit(0);

const int mod = (int)1e9 + 7;
const int N = (int)1e4;

using namespace std;

void add(int &x, int y) {
  x += y;
  if (x >= mod) x -= mod;
  if (x < 0) x += mod;
}
int sum(int x, int y) {
  add(x, y);
  return x;
}
int n, m;

int dp[3001][3001];
int main() {
  #ifdef IOI
    freopen ("in.txt", "r", stdin);
    freopen ("slow.out", "w", stdout);
  #endif
  cin >> n >> m;
  /* memset(dp, -1, sizeof(dp));
  int ans = sum(calc(), -1);
  cout << ans << nl; */
  dp[0][m] = 1;
  rep(i, 0, n - 1) {
    rep(j, 0, m) {
      // skip
      add(dp[i + 1][j], dp[i][j]);
      // put any char
      if (j > 0) add(dp[i + 1][j - 1], dp[i][j] * 1ll * 4 * j % mod);
      // put > and <
      if (j > 1) add(dp[i + 1][j - 2], dp[i][j] * 1ll * (j * (j - 1) / 2) % mod);
      // put v and ^
      if (i + 2 <= n && j > 0) add(dp[i + 2][j - 1], dp[i][j] * 1ll * (n - i - 1) * j % mod);
    }
  }
  int ans = -1;
  rep(i, 0, m) add(ans, dp[n][i]);
  cout << ans;
  ioi
}

/*

5116 0
3720 1
450 2

*/

Subtask #1
48.0 / 48.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 256 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 504 KB Output is correct
4 Correct 3 ms 1016 KB Output is correct
5 Correct 3 ms 632 KB Output is correct
6 Correct 4 ms 1272 KB Output is correct
7 Correct 3 ms 760 KB Output is correct
8 Correct 3 ms 1404 KB Output is correct
9 Correct 3 ms 888 KB Output is correct
10 Correct 5 ms 1656 KB Output is correct
11 Correct 2 ms 376 KB Output is correct
12 Correct 6 ms 1912 KB Output is correct

Subtask #2
52.0 / 52.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 256 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 504 KB Output is correct
4 Correct 3 ms 1016 KB Output is correct
5 Correct 3 ms 632 KB Output is correct
6 Correct 4 ms 1272 KB Output is correct
7 Correct 3 ms 760 KB Output is correct
8 Correct 3 ms 1404 KB Output is correct
9 Correct 3 ms 888 KB Output is correct
10 Correct 5 ms 1656 KB Output is correct
11 Correct 2 ms 376 KB Output is correct
12 Correct 6 ms 1912 KB Output is correct
13 Correct 2 ms 376 KB Output is correct
14 Correct 13 ms 9596 KB Output is correct
15 Correct 175 ms 32912 KB Output is correct
16 Correct 9 ms 2680 KB Output is correct
17 Correct 32 ms 7928 KB Output is correct
18 Correct 50 ms 11000 KB Output is correct
19 Correct 199 ms 34556 KB Output is correct
20 Correct 158 ms 29060 KB Output is correct
21 Correct 101 ms 19836 KB Output is correct
22 Correct 109 ms 22264 KB Output is correct
23 Correct 74 ms 19832 KB Output is correct
24 Correct 251 ms 35576 KB Output is correct
25 Correct 192 ms 30736 KB Output is correct
26 Correct 219 ms 33536 KB Output is correct
27 Correct 241 ms 34664 KB Output is correct