g0701_0800.s0745_prefix_and_suffix_search

Class WordFilter

java.lang.Object

g0701_0800.s0745_prefix_and_suffix_search.WordFilter

public class WordFilter
extends Object

745 - Prefix and Suffix Search.

Hard

Design a special dictionary with some words that searchs the words in it by a prefix and a suffix.

Implement the WordFilter class:

• WordFilter(string[] words) Initializes the object with the words in the dictionary.
• f(string prefix, string suffix) Returns the index of the word in the dictionary, which has the prefix prefix and the suffix suffix. If there is more than one valid index, return the largest of them. If there is no such word in the dictionary, return -1.

Example 1:

Input

[“WordFilter”, “f”]

["apple", [“a”, “e”]]

Output: [null, 0]

Explanation:

WordFilter wordFilter = new WordFilter(["apple"]); 
wordFilter.f("a", "e"); // return 0, because the word at index 0 has prefix = "a" and suffix = 'e".

Constraints:

• 1 <= words.length <= 15000
• 1 <= words[i].length <= 10
• 1 <= prefix.length, suffix.length <= 10
• words[i], prefix and suffix consist of lower-case English letters only.
• At most 15000 calls will be made to the function f.

Constructor Summary

Constructors

Constructor and Description
WordFilter(String[] words)

Method Summary

Modifier and Type	Method and Description
int	f(String prefix, String suffix)
void	insert(String wd, int weight)
int	startsWith(String pref)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

WordFilter

public WordFilter(String[] words)

Method Detail

insert

public void insert(String wd,
                   int weight)

f

public int f(String prefix,
             String suffix)

startsWith

public int startsWith(String pref)