LeetCode 中级算法（数组和字符串）-字谜分组
字谜分组
给定一个字符串数组，将字母异位词组合在一起。字母异位词指字母相同，但排列不同的字符串。
示例:
输入: ["eat", "tea", "tan", "ate", "nat", "bat"],
输出:
[
["ate","eat","tea"],
["nat","tan"],
["bat"]
]
说明：
所有输入均为小写字母。
不考虑答案输出的顺序。
Python：
第一次解法：超时的
class Solution(object):
def groupAnagrams(self, strs):
"""
:type strs: List[str]
:rtype: List[List[str]]
"""
result = []
letter_list = []
temp_list = []
str_myset = set(strs)
if len(set(strs)) == 1:
for value in strs:
letter_list.append(value)
result.append(letter_list)
return result
for w in range(ord("a"),ord("z") + 1):
letter_list.append(chr(w))
res = []
dic_set = []
for str_value in strs:
dic_val = {}
if str_value == "":
temp_list.append(str_value)
pass
for char in str_value:
if char in dic_val:
dic_val[char] +=1
else:
dic_val[char] = 1
if dic_val not in res and len(dic_val) > 0:
dic_set.append(dic_val)
res.append(dic_val)
for value in dic_set:
lis_a = []
for idx in range(len(res)):
if value == res[idx]:
lis_a.append(strs[idx])
pass
result.append(lis_a)
if len(temp_list) > 0:
result.append(temp_list)
return result
优化后的：
还是超时！！??
class Solution(object):
def groupAnagrams(self, strs):
"""
:type strs: List[str]
:rtype: List[List[str]]
"""
length_d = len(strs)
sorted_list = []
res = []
for i in range(length_d):
if sorted(strs[i]) not in sorted_list:
sorted_list.append(sorted(strs[i]))
for value in sorted_list:
list_a = []
for i in range(length_d):
if value == sorted(strs[i]):
list_a.append(strs[i])
res.append(list_a)
return res
再次优化：
class Solution(object):
def groupAnagrams(self, strs):
"""
:type strs: List[str]
:rtype: List[List[str]]
"""
length_d = len(strs)
sorted_list = []
res = []
for i in range(length_d):
lis_a = []
if sorted(strs[i]) not in sorted_list:
sorted_list.append(sorted(strs[i]))
index = sorted_list.index(sorted(strs[i]))
if len(res) > index:
res[index].append(strs[i])
pass
else:
lis_a.append(strs[i])
res.append(lis_a)
return res
??勉强过
再再再再。。次优化：
class Solution(object):
def groupAnagrams(self, strs):
"""
:type strs: List[str]
:rtype: List[List[str]]
"""
res = {}
for value in strs:
list_a = []
char = "".join(sorted(value))
if char not in res:
list_a.append(value)
res[char] = list_a
else:
res[char].append(value)
# print(res)
return res.values()
下面是大佬的：
1：
class Solution(object):
def groupAnagrams(self, strs):
"""
:type strs: List[str]
:rtype: List[List[str]]
"""
hash = {}
for str in strs:
char = ''.join(sorted(str))
if char not in hash:
hash[char] = [str]
else:
hash[char].append(str)
return hash.values()
2：
class Solution(object):
def groupAnagrams(self, strs):
"""
:type strs: List[str]
:rtype: List[List[str]]
"""
dic = dict()
result = []
classnum = 0
for item in strs:
l = list(item)
l.sort()
string = str(l)
if dic.has_key(string):
result[dic[string]].append(item)
else:
dic[string] = classnum
result.append([item])
classnum += 1
return result