結果
問題 |
No.1117 数列分割
|
ユーザー |
![]() |
提出日時 | 2025-04-15 23:06:20 |
言語 | PyPy3 (7.3.15) |
結果 |
AC
|
実行時間 | 2,173 ms / 3,000 ms |
コード長 | 2,220 bytes |
コンパイル時間 | 304 ms |
コンパイル使用メモリ | 81,908 KB |
実行使用メモリ | 94,076 KB |
最終ジャッジ日時 | 2025-04-15 23:08:33 |
合計ジャッジ時間 | 25,538 ms |
ジャッジサーバーID (参考情報) |
judge5 / judge2 |
(要ログイン)
ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 26 |
ソースコード
import sys from collections import deque def main(): import sys input = sys.stdin.read().split() idx = 0 N = int(input[idx]); idx +=1 K = int(input[idx]); idx +=1 M = int(input[idx]); idx +=1 A = list(map(int, input[idx:idx+N])) idx += N # Prefix sum array (1-based) S = [0] * (N + 1) for i in range(1, N+1): S[i] = S[i-1] + A[i-1] # Initialize DP with two arrays for space optimization prev_dp = [-float('inf')] * (N + 1) prev_dp[0] = 0 # base case: 0 elements, 0 segments for k in range(1, K+1): curr_dp = [-float('inf')] * (N + 1) que1 = deque() # for max (dp[j] - S[j]) que2 = deque() # for max (dp[j] + S[j]) for i in range(1, N+1): left = max(0, i - M) # Remove outdated elements from the front of the queues while que1 and que1[0] < left: que1.popleft() while que2 and que2[0] < left: que2.popleft() # Add j = i-1 to the queues if valid j = i - 1 if j >= 0 and prev_dp[j] != -float('inf'): val1 = prev_dp[j] - S[j] # Maintain que1 in decreasing order of val1 while que1 and (prev_dp[que1[-1]] - S[que1[-1]] <= val1): que1.pop() que1.append(j) val2 = prev_dp[j] + S[j] # Maintain que2 in decreasing order of val2 while que2 and (prev_dp[que2[-1]] + S[que2[-1]] <= val2): que2.pop() que2.append(j) # Calculate the maximum possible value for current i and k max_val = -float('inf') if que1: current_val = (prev_dp[que1[0]] - S[que1[0]]) + S[i] if current_val > max_val: max_val = current_val if que2: current_val = (prev_dp[que2[0]] + S[que2[0]]) - S[i] if current_val > max_val: max_val = current_val if max_val != -float('inf'): curr_dp[i] = max_val prev_dp = curr_dp print(prev_dp[N]) if __name__ == '__main__': main()