add 676

Author: fishercoder1534

README.md

@@ -22,6 +22,8 @@ Your ideas/fixes/algorithms are more than welcome!
 
 |  #  |      Title     |   Solutions   | Time          | Space         | Difficulty  | Tag          | Notes
 |-----|----------------|---------------|---------------|---------------|-------------|--------------|-----
+|676|[Implement Magic Dictionary](https://leetcode.com/problems/implement-magic-dictionary/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_676.java) | O(n^2) | O(n) | Medium |
+|674|[Longest Continuous Increasing Subsequence](https://leetcode.com/problems/longest-continuous-increasing-subsequence/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_674.java) | O(n^2) | O(1) | Easy | 
 |672|[Bulb Switcher II](https://leetcode.com/problems/bulb-switcher-ii/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_672.java) | O(1) | O(1) | Medium | Math 
 |671|[Second Minimum Node In a Binary Tree](https://leetcode.com/problems/second-minimum-node-in-a-binary-tree/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_671.java) | O(n) | O(n) | Easy | Tree, DFS
 |670|[Maximum Swap](https://leetcode.com/problems/maximum-swap/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_670.java) | O(n^2) | O(1) | Medium | String

src/main/java/com/fishercoder/solutions/_676.java

@@ -0,0 +1,83 @@
+package com.fishercoder.solutions;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * 676. Implement Magic Dictionary
+ * Implement a magic directory with buildDict, and search methods.
+ * For the method buildDict, you'll be given a list of non-repetitive words to build a dictionary.
+ * For the method search, you'll be given a word,
+ * and judge whether if you modify exactly one character into another character in this word,
+ * the modified word is in the dictionary you just built.
+
+ Example 1:
+
+ Input: buildDict(["hello", "leetcode"]), Output: Null
+ Input: search("hello"), Output: False
+ Input: search("hhllo"), Output: True
+ Input: search("hell"), Output: False
+ Input: search("leetcoded"), Output: False
+
+ Note:
+
+ You may assume that all the inputs are consist of lowercase letters a-z.
+ For contest purpose, the test data is rather small by now.
+ You could think about highly efficient algorithm after the contest.
+ Please remember to RESET your class variables declared in class MagicDictionary,
+ as static/class variables are persisted across multiple test cases. Please see here for more details.
+
+ */
+public class _676 {
+
+    public static class Solution1 {
+        public static class MagicDictionary {
+
+            Set<String> wordSet;
+
+            /**
+             * Initialize your data structure here.
+             */
+            public MagicDictionary() {
+                wordSet = new HashSet<>();
+            }
+
+            /**
+             * Build a dictionary through a list of words
+             */
+            public void buildDict(String[] dict) {
+                for (String word : dict) {
+                    wordSet.add(word);
+                }
+            }
+
+            /**
+             * Returns if there is any word in the trie that equals to the given word after modifying exactly one character
+             */
+            public boolean search(String word) {
+                for (String candidate : wordSet) {
+                    if (modifyOneChar(word, candidate)) {
+                        return true;
+                    }
+                }
+                return false;
+            }
+
+            private boolean modifyOneChar(String word, String candidate) {
+                if (word.length() != candidate.length()) {
+                    return false;
+                }
+                int diff = 0;
+                for (int i = 0; i < word.length(); i++) {
+                    if (word.charAt(i) != candidate.charAt(i)) {
+                        diff++;
+                    }
+                    if (diff > 1) {
+                        return false;
+                    }
+                }
+                return diff == 1;
+            }
+        }
+    }
+}

src/test/java/com/fishercoder/_676Test.java

@@ -0,0 +1,31 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._676;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class _676Test {
+    private static _676.Solution1.MagicDictionary magicDictionarySol1;
+
+    @BeforeClass
+    public static void setup() {
+        magicDictionarySol1 = new _676.Solution1.MagicDictionary();
+    }
+
+    @Before
+    public void cleanup() {
+        magicDictionarySol1 = new _676.Solution1.MagicDictionary();
+    }
+
+    @Test
+    public void test1() {
+        magicDictionarySol1.buildDict(new String[]{"hello", "leetcode"});
+        assertEquals(false, magicDictionarySol1.search("hello"));
+        assertEquals(true, magicDictionarySol1.search("hhllo"));
+        assertEquals(false, magicDictionarySol1.search("hell"));
+        assertEquals(false, magicDictionarySol1.search("leetcoded"));
+    }
+}