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Java-based LeetCode algorithm problem solutions, regularly updated

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package g0201_0300.s0290_word_pattern;

// #Easy #String #Hash_Table #Data_Structure_II_Day_7_String
// #2022_07_06_Time_1_ms_(97.26%)_Space_40.4_MB_(85.78%)

import java.util.HashMap;
import java.util.Map;

/**
 * 290 - Word Pattern\.
 *
 * Easy
 *
 * Given a `pattern` and a string `s`, find if `s` follows the same pattern.
 *
 * Here **follow** means a full match, such that there is a bijection between a letter in `pattern` and a **non-empty** word in `s`.
 *
 * **Example 1:**
 *
 * **Input:** pattern = "abba", s = "dog cat cat dog"
 *
 * **Output:** true 
 *
 * **Example 2:**
 *
 * **Input:** pattern = "abba", s = "dog cat cat fish"
 *
 * **Output:** false 
 *
 * **Example 3:**
 *
 * **Input:** pattern = "aaaa", s = "dog cat cat dog"
 *
 * **Output:** false 
 *
 * **Example 4:**
 *
 * **Input:** pattern = "abba", s = "dog dog dog dog"
 *
 * **Output:** false 
 *
 * **Constraints:**
 *
 * *   `1 <= pattern.length <= 300`
 * *   `pattern` contains only lower-case English letters.
 * *   `1 <= s.length <= 3000`
 * *   `s` contains only lower-case English letters and spaces `' '`.
 * *   `s` **does not contain** any leading or trailing spaces.
 * *   All the words in `s` are separated by a **single space**.
**/
public class Solution {
    public boolean wordPattern(String pattern, String s) {
        Map map = new HashMap<>();
        String[] words = s.split(" ");
        if (words.length != pattern.length()) {
            return false;
        }
        for (int i = 0; i < pattern.length(); i++) {
            if (!map.containsKey(pattern.charAt(i))) {
                if (map.containsValue(words[i])) {
                    return false;
                }
                map.put(pattern.charAt(i), words[i]);
            } else {
                if (!words[i].equals(map.get(pattern.charAt(i)))) {
                    return false;
                }
            }
        }
        return true;
    }
}