結果

問題 No.2858 Make a Palindrome
ユーザー square1001
提出日時 2024-07-15 11:49:25
言語 PyPy3
(7.3.15)
結果
AC  
実行時間 1,012 ms / 3,000 ms
コード長 1,066 bytes
コンパイル時間 225 ms
コンパイル使用メモリ 82,192 KB
実行使用メモリ 353,792 KB
最終ジャッジ日時 2024-07-15 11:49:48
合計ジャッジ時間 21,623 ms
ジャッジサーバーID
(参考情報)
judge4 / judge5
このコードへのチャレンジ
(要ログイン)
ファイルパターン 結果
other AC * 40
権限があれば一括ダウンロードができます

ソースコード

diff #
プレゼンテーションモードにする

# taken from https://tjkendev.github.io/procon-library/python/string/manacher.html
def manacher(S):
C = []
for a in S:
C.append(a)
C.append(0)
C.pop()
L = len(C)
R = [0]*L
i = j = 0
while i < L:
while j <= i < L-j and C[i-j] == C[i+j]:
j += 1
R[i] = j
k = 1
while j-R[i-k] > k <= i < L-k:
R[i+k] = R[i-k]
k += 1
i += k; j -= k
for i in range(L):
if i & 1 == R[i] & 1:
R[i] -= 1
return R
def longest_palindrome(s):
return max(manacher(s))
def solve(n, m, s):
v1 = longest_palindrome(s * 1)
v2 = longest_palindrome(s * 2)
v3 = longest_palindrome(s * 3)
v4 = longest_palindrome(s * 4)
if v1 >= m:
return 1
if v2 >= m:
return 2
if v3 >= m:
return 3
ans = -1
if v3 >= 2 * n:
subans = 3 + (m - v3 + 2 * n - 1) // (2 * n) * 2
ans = (subans if ans == -1 else min(ans, subans))
if v4 >= 2 * n:
subans = 4 + (m - v4 + 2 * n - 1) // (2 * n) * 2
ans = (subans if ans == -1 else min(ans, subans))
return ans
t = int(input())
for _ in range(t):
n, m = map(int, input().split())
s = input()
print(solve(n, m, s))
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
0