結果
問題 |
No.1867 Partitions and Inversions
|
ユーザー |
![]() |
提出日時 | 2025-05-14 12:51:40 |
言語 | PyPy3 (7.3.15) |
結果 |
TLE
|
実行時間 | - |
コード長 | 1,514 bytes |
コンパイル時間 | 321 ms |
コンパイル使用メモリ | 82,608 KB |
実行使用メモリ | 298,640 KB |
最終ジャッジ日時 | 2025-05-14 12:52:44 |
合計ジャッジ時間 | 6,855 ms |
ジャッジサーバーID (参考情報) |
judge5 / judge4 |
(要ログイン)
ファイルパターン | 結果 |
---|---|
sample | -- * 3 |
other | AC * 2 TLE * 1 -- * 62 |
ソースコード
def main(): import sys input = sys.stdin.read().split() idx = 0 N = int(input[idx]) idx += 1 P = list(map(int, input[idx:idx+N])) idx += N # Compute cross matrix cross = [[0] * (N + 1) for _ in range(N + 1)] # cross[i][j] is the number of elements in P[1..i] > P[j] for j in range(1, N + 1): current = 0 for i in range(0, N + 1): if i == 0: cross[i][j] = 0 else: cross[i][j] = cross[i - 1][j] + (1 if P[i - 1] > P[j - 1] else 0) # Precompute sum_after_l[l][r] = sum_{j=l+1 to r} cross[l][j] sum_after_l = [[0] * (N + 1) for _ in range(N + 1)] for l in range(N + 1): current_sum = 0 for r in range(l + 1, N + 1): current_sum += cross[l][r] sum_after_l[l][r] = current_sum # Compute total_inv (not needed here) # total_inv = sum_after_l[0][N] # Initialize DP INF = float('inf') dp = [ [INF] * (N + 1) for _ in range(N + 1) ] dp[0][0] = 0 for k in range(1, N + 1): for i in range(k, N + 1): if k == 1: dp[k][i] = sum_after_l[0][i] else: min_val = INF for j in range(k - 1, i): if dp[k - 1][j] + sum_after_l[j][i] < min_val: min_val = dp[k - 1][j] + sum_after_l[j][i] dp[k][i] = min_val for k in range(1, N + 1): print(dp[k][N]) if __name__ == '__main__': main()