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:
words1 and words2 will not exceed 1000.pairs will not exceed 2000.pairs[i] will be 2.words[i] and pairs[i][j] will be in the range [1, 20].Intuition and Algorithm
To check whether words1[i] and words2[i] are similar, either they are the same word, or (words1[i], words2[i]) or (words2[i], words1[i]) appear in pairs.
To check whether (words1[i], words2[i]) appears in pairs quickly, we could put all such pairs into a Set structure.
Complexity Analysis
Time Complexity: , where is the maximum length of words1 and words2, and is the length of pairs.
Space Complexity: , the size of pairs. Intermediate objects created in evaluating whether a pair of words are similar are created one at a time, so they don't take additional space.
Analysis written by: @awice.