根据第N个单词对句子排序

Question

I have to read a file with one sentence on each line.
Then I have to sort these sentences based on the N ^th word (I am given a number as an input parameter which represents the place of the sort-by-this word in the sentence).

File reading is done and I have loaded the words in a two-dimensional string array.

for(String line : Files.readAllLines(file))
for(String word : line.trim().split(" "))

How should I sort the sentences?

Answer 1

Use a custom Comparator<String> , to parametrize your sort invocation (invoked on either a Collection or an Array , through the Collections or Arrays utility classes respectively).

• You will need to have an instance field in your Comparator , that will represent the Nth word's index you base your sorting on, and a setter or constructor to set it
• In your compare(String s1, String s2) override, you will use that field to check whether both String s are long enough and have enough actual words (then, also decide what to do if either doesn't qualify)
• If both String s qualify, you will pick those words by itemizing them through a Scanner or Pattern , and return the computation of compare on those two words, instead of the whole String s
• That will guarantee that given a list of String s and a word index, all String s qualifying to have a separable word at that given word index will be compared based on the lexicographical comparison of those words, and a separate logic for those String s that do not qualify