add 2451

Author: fishercoder1534

Diff for: paginated_contents/algorithms/3rd_thousand/README.md

@@ -49,6 +49,7 @@
 | 2485 | [Find the Pivot Integer](https://leetcode.com/problems/find-the-pivot-integer/)                                                                                 | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/thirdthousand/_2485.java)                                       || Easy                                 ||
 | 2467 | [Convert the Temperature](https://leetcode.com/problems/convert-the-temperature/)                                                                                                            | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/thirdthousand/_2469.java)                                       || Easy                                 ||
 | 2455 | [Average Value of Even Numbers That Are Divisible by Three](https://leetcode.com/problems/average-value-of-even-numbers-that-are-divisible-by-three/)                                        | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/thirdthousand/_2455.java)                                       || Easy                                 ||
+| 2451 | [Odd String Difference](https://leetcode.com/problems/odd-string-difference/)                                                                                                            | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/thirdthousand/_2451.java)                                       || Easy                                 |
 | 2446 | [Determine if Two Events Have Conflict](https://leetcode.com/problems/determine-if-two-events-have-conflict/)                                                                                                            | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/thirdthousand/_2446.java)                                       || Easy                                 |
 | 2441 | [Largest Positive Integer That Exists With Its Negative](https://leetcode.com/problems/largest-positive-integer-that-exists-with-its-negative/)                                                                                                            | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/thirdthousand/_2441.java)                                       || Easy                                 ||
 | 2437 | [Number of Valid Clock Times](https://leetcode.com/problems/number-of-valid-clock-times/)                                                                                | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/thirdthousand/_2437.java)                                       |                                      | Easy                           ||

Diff for: src/main/java/com/fishercoder/solutions/thirdthousand/_2451.java

@@ -0,0 +1,34 @@
+package com.fishercoder.solutions.thirdthousand;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class _2451 {
+    public static class Solution1 {
+        public String oddString(String[] words) {
+            Map<List<Integer>, List<String>> map = new HashMap<>();
+            for (String word : words) {
+                List<Integer> diffs = computeDiff(word);
+                List<String> list = map.getOrDefault(diffs, new ArrayList<>());
+                list.add(word);
+                map.put(diffs, list);
+            }
+            for (Map.Entry<List<Integer>, List<String>> entry : map.entrySet()) {
+                if (entry.getValue().size() == 1) {
+                    return entry.getValue().get(0);
+                }
+            }
+            return null;
+        }
+
+        private List<Integer> computeDiff(String word) {
+            List<Integer> diffs = new ArrayList<>();
+            for (int i = 0; i < word.length() - 1; i++) {
+                diffs.add(word.charAt(i + 1) - word.charAt(i));
+            }
+            return diffs;
+        }
+    }
+}

Diff for: src/test/java/com/fishercoder/thirdthousand/_2451Test.java

@@ -0,0 +1,32 @@
+package com.fishercoder.thirdthousand;
+
+import com.fishercoder.solutions.thirdthousand._2451;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class _2451Test {
+    private static _2451.Solution1 solution1;
+
+    @BeforeEach
+    public void setup() {
+        solution1 = new _2451.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        assertEquals("abc", solution1.oddString(new String[]{"adc", "wzy", "abc"}));
+    }
+
+    @Test
+    public void test2() {
+        assertEquals("aaaabbbbbbaaabaaaabb", solution1.oddString(new String[]{"nnnmmmnnmmmmmmmmmmnm", "iiihhhiihhhhhhhhhhih", "aaaabbbbbbaaabaaaabb", "qqqpppqqppppppppppqp", "eeedddeedddddddddded", "eeedddeedddddddddded", "iiihhhiihhhhhhhhhhih", "lllkkkllkkkkkkkkkklk", "sssrrrssrrrrrrrrrrsr", "sssrrrssrrrrrrrrrrsr", "jjjiiijjiiiiiiiiiiji", "nnnmmmnnmmmmmmmmmmnm", "xxxwwwxxwwwwwwwwwwxw", "eeedddeedddddddddded", "zzzyyyzzyyyyyyyyyyzy", "wwwvvvwwvvvvvvvvvvwv", "cccbbbccbbbbbbbbbbcb", "xxxwwwxxwwwwwwwwwwxw", "cccbbbccbbbbbbbbbbcb", "yyyxxxyyxxxxxxxxxxyx", "hhhggghhgggggggggghg"}));
+    }
+
+    @Test
+    public void test3() {
+        assertEquals("abb", solution1.oddString(new String[]{"mll", "abb", "edd", "jii", "tss", "fee", "dcc", "nmm", "utt", "zyy", "xww", "tss", "wvv", "xww", "utt"}));
+    }
+
+}