890. Find and Replace Pattern(python+cpp)
阿新 • • 發佈:2018-11-16
題目:
You have a list of
words
and apattern
, and you want to know which words inwords
matches the pattern.
A word matches the pattern if there exists a permutation of lettersp
so that after replacing every letter x in the pattern with p(x), we get the desired word.
(Recall that a permutation of letters is a bijection from letters to letters: every letter maps to another letter, and no two letters map to the same letter.)
Return a list of the words inwords
that match the given pattern.
You may return the answer in any ord
Example 1:Input: words = ["abc","deq","mee","aqq","dkd","ccc"], pattern = "abb" Output: ["mee","aqq"] Explanation: "mee" matches the pattern because there is a permutation {a -> m, b -> e, ...}. "ccc" does not match the pattern because {a -> c, b -> c, ...} is not a permutation, since a and b map to the same letter.
Note:
1 <= words.length <= 50
1 <= pattern.length = words[i].length <= 20
解釋:
與205. Isomorphic Strings(python+cpp)和290. Word Pattern(python+cpp)寫法一樣,用兩個字典實現。205的程式碼可以直接使用,可以把word pattern的過程寫成一個函式。
python程式碼:
class Solution:
def findAndReplacePattern(self, words, pattern):
"""
:type words: List[str]
:type pattern: str
:rtype: List[str]
"""
def isIsomorphic(s, t):
if len(s)!=len(t):
return False
s_dict={}
t_dict={}
for i in range(len(s)):
if s[i] not in s_dict:
s_dict[s[i]]=t[i]
else:
if s_dict[s[i]]==t[i]:
continue
else:
return False
if t[i] in t_dict:
if t_dict[t[i]]!=s[i]:
return False
else:
t_dict[t[i]]=s[i]
return True
result=[ word for word in words if isIsomorphic(word,pattern)]
return result
c++程式碼:
class Solution {
public:
vector<string> findAndReplacePattern(vector<string>& words, string pattern) {
vector<string> result;
for (auto word:words)
{
if (isIsomorphic(word,pattern))
result.push_back(word);
}
return result;
}
bool isIsomorphic(string s,string t)
{
if (s.size()!=t.size())
return false;
map<char,char>s_map;
map<char,char>t_map;
for (int i=0;i<s.size();i++)
{
if (!s_map.count(s[i]))
s_map[s[i]]=t[i];
else
{
//這裡寫continue而不是直接省略更加節省時間,可以結合具體案例看一下。
if (s_map[s[i]]==t[i])
continue;
else
return false;
}
if (t_map.count(t[i]))
{
if (t_map[t[i]]!=s[i])
return false;
}
else
t_map[t[i]]=s[i];
}
return true;
}
};
總結: