Problem:
Given two sentences words1, words2 (each represented as an array of strings), and a list of similar word pairs pairs, determine if two sentences are similar. For example, “great acting skills” and “fine drama talent” are similar, if the similar word pairs are pairs = [[“great”, “fine”], [“acting”,”drama”], [“skills”,”talent”]]. Note that the similarity relation is not transitive. For example, if “great” and “fine” are similar, and “fine” and “good” are similar, “great” and “good” are not necessarily similar. However, similarity is symmetric. For example, “great” and “fine” being similar is the same as “fine” and “great” being similar. Also, a word is always similar with itself. For example, the sentences words1 = [“great”], words2 = [“great”], pairs = [] are similar, even though there are no specified similar word pairs. Finally, sentences can only be similar if they have the same number of words. So a sentence like words1 = [“great”] can never be similar to words2 = [“doubleplus”,”good”].
Note:
The length of words1 and words2 will not exceed 1000.
The length of pairs will not exceed 2000.
The length of each pairs[i] will be 2.
The length of each words[i] and pairs[i][j] will be in the range [1, 20].
思路: 查询每个单词是否有对应的近义词,如果找不到则返回false。
Java版:
public boolean areSentencesSimilar(String[] words1, String[] words2, String[][] pairs) {
if (words1.length != words2.length) return false;
Map<String, Set<String>> map = new HashMap<>();
for (String[] p : pairs) {
map.computeIfAbsent(p[0], k -> new HashSet<>()).add(p[1]);
}
for (int i = 0; i < words1.length; ++i) {
String a = words1[i];
String b = words2[i];
if (!a.equals(b)) {
if (!map.getOrDefault(a, new HashSet<>()).contains(b) && !map.getOrDefault(b, new HashSet<>()).contains(a)) return false;
}
}
return true;
}
Python版:
def areSentencesSimilar(self, words1, words2, pairs):
"""
:type words1: List[str]
:type words2: List[str]
:type pairs: List[List[str]]
:rtype: bool
"""
from collections import defaultdict
n1 = len(words1)
n2 = len(words2)
if n1 != n2:
return False
map = defaultdict(set)
for word1, word2 in pairs:
map[word1].add(word2)
for word1, word2 in zip(words1, words2):
if word1 != word2 and word2 not in map[word1] and word1 not in map[word2]:
return False
return True
Python 注意 all 的使用:
all([…]) or all((…)) 所有元素不为空,不为0,不为Flase,则返回True
def areSentencesSimilar(self, words1, words2, pairs):
"""
:type words1: List[str]
:type words2: List[str]
:type pairs: List[List[str]]
:rtype: bool
"""
from collections import defaultdict
n1 = len(words1)
n2 = len(words2)
if n1 != n2:
return False
map = defaultdict(set)
for w in words1:
map[w].add(w)
for w in words2:
map[w].add(w)
for word1, word2 in pairs:
map[word1].add(word2)
map[word2].add(word1)
return all(b in map[a] for a, b in zip(words1, words2))