結果
問題 |
No.1867 Partitions and Inversions
|
ユーザー |
![]() |
提出日時 | 2025-06-12 14:49:19 |
言語 | PyPy3 (7.3.15) |
結果 |
TLE
|
実行時間 | - |
コード長 | 1,540 bytes |
コンパイル時間 | 145 ms |
コンパイル使用メモリ | 82,420 KB |
実行使用メモリ | 226,716 KB |
最終ジャッジ日時 | 2025-06-12 14:52:47 |
合計ジャッジ時間 | 6,896 ms |
ジャッジサーバーID (参考情報) |
judge5 / judge3 |
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ファイルパターン | 結果 |
---|---|
sample | -- * 3 |
other | AC * 2 TLE * 1 -- * 62 |
ソースコード
import sys def main(): sys.setrecursionlimit(1 << 25) N = int(sys.stdin.readline()) P = list(map(int, sys.stdin.readline().split())) # Precompute inv[l][r] for all 1 <= l <= r <= N inv = [[0]*(N+1) for _ in range(N+1)] # 1-based for l in range(1, N+1): fenwick = [0]*(N+2) # 1-based to N total = 0 for r in range(l, N+1): x = P[r-1] # count number of elements already in the Fenwick tree > x # which is (current_size) - query(x) current_size = r - l pos = x res = current_size while pos > 0: res -= fenwick[pos] pos -= pos & -pos total += res # update Fenwick tree pos = x while pos <= N: fenwick[pos] += 1 pos += pos & -pos inv[l][r] = total original = inv[1][N] # Initialize DP max_k = N dp = [ [ -float('inf') ]*(N+2) for _ in range(max_k+2) ] dp[0][0] = 0 for j in range(1, max_k+1): current_dp = [ -float('inf') ]*(N+2) for i in range(1, N+1): for l in range(0, i): val = dp[j-1][l] + inv[l+1][i] if val > current_dp[i]: current_dp[i] = val dp[j] = current_dp for k in range(1, N+1): max_sum = max(dp[k][i] for i in range(N+1)) ans = original - max_sum print(ans) if __name__ == '__main__': main()