我正在做Leetcode上的一个问题,题目是:找到最长回文子串。
例如,如果输入为babad,则输出可以是bab或aba。
或者
如果输入为cbbd,则输出为bb。
我相当确定已经想出来了,这是我的代码......
def longestPalindrome(self, s):
n = len(s)
# Empty matrix.
table = [[False for i in range(n)] for j in range(n)]
# Identity matrix.
for i in range(n):
table[i][i] = True
max_len = 0
start = 0
finish = 0
for sil in range(2, n+1):
for i in range(n-sil + 1):
j = sil + i - 1
if sil == 2:
if s[i] == s[j]:
table[i][j] = True
max_len = j-i
start = i
finish = j
else:
if s[i] == s[j] and table[i+1][j-1]:
table[i][j] = True
if (j - i) > finish-start:
max_len = j - i
start = i
finish = j
return s[start:finish+1]
它适用于大多数情况,但当字符串非常长时会出现问题。我正在提交我的代码,但在以下情况下失败了...
"esbtzjaaijqkgmtaajpsdfiqtvxsgfvijpxrvxgfumsuprzlyvhclgkhccmcnquukivlpnjlfteljvykbddtrpmxzcrdqinsnlsteonhcegtkoszzonkwjevlasgjlcquzuhdmmkhfniozhuphcfkeobturbuoefhmtgcvhlsezvkpgfebbdbhiuwdcftenihseorykdguoqotqyscwymtjejpdzqepjkadtftzwebxwyuqwyeegwxhroaaymusddwnjkvsvrwwsmolmidoybsotaqufhepinkkxicvzrgbgsarmizugbvtzfxghkhthzpuetufqvigmyhmlsgfaaqmmlblxbqxpluhaawqkdluwfirfngbhdkjjyfsxglsnakskcbsyafqpwmwmoxjwlhjduayqyzmpkmrjhbqyhongfdxmuwaqgjkcpatgbrqdllbzodnrifvhcfvgbixbwywanivsdjnbrgskyifgvksadvgzzzuogzcukskjxbohofdimkmyqypyuexypwnjlrfpbtkqyngvxjcwvngmilgwbpcsseoywetatfjijsbcekaixvqreelnlmdonknmxerjjhvmqiztsgjkijjtcyetuygqgsikxctvpxrqtuhxreidhwcklkkjayvqdzqqapgdqaapefzjfngdvjsiiivnkfimqkkucltgavwlakcfyhnpgmqxgfyjziliyqhugphhjtlllgtlcsibfdktzhcfuallqlonbsgyyvvyarvaxmchtyrtkgekkmhejwvsuumhcfcyncgeqtltfmhtlsfswaqpmwpjwgvksvazhwyrzwhyjjdbphhjcmurdcgtbvpkhbkpirhysrpcrntetacyfvgjivhaxgpqhbjahruuejdmaghoaquhiafjqaionbrjbjksxaezosxqmncejjptcksnoq"
错误提示为“时间限制超出”。为什么会出现这种情况呢?我正在使用动态规划解决方案,应该是一个被接受的答案。