Add solution for One Edit Distance

Author: jihyun-um

README.md

@@ -7,6 +7,7 @@ Algorithm exercises from LeetCode implemented in Java v11.
 - Sorting Sentence | [Problem](https://leetcode.com/problems/sorting-the-sentence) | [Solution](src/solutions/SortingSentence.java)
 - Student Attendance Record I | [Problem](https://leetcode.com/problems/student-attendance-record-i) | [Solution](src/solutions/StudentAttendanceRecord.java)
 - Reverse Words in a String III | [Problem](https://leetcode.com/problems/reverse-words-in-a-string-iii) | [Solution](src/solutions/ReverseWordsInStringIII.java)
+- One Edit Distance | [Problem](https://leetcode.com/problems/one-edit-distance) | [Solution](src/solutions/OneEditDistance.java)
 
 ### Array
 - Jewels and Stones | [Problem](https://leetcode.com/problems/jewels-and-stones) | [Solution](src/solutions/JewelsAndStones.java)

src/solutions/OneEditDistance.java

@@ -0,0 +1,33 @@
+package solutions;
+
+// [Problem] https://leetcode.com/problems/one-edit-distance
+class OneEditDistance {
+    // String
+    // O(n) time, O(n) space
+    public boolean isOneEditDistance(String s, String t) {
+        int sLength = s.length(), tLength = t.length();
+        for (int i = 0; i < Math.min(sLength, tLength); i++) {
+            if (s.charAt(i) != t.charAt(i)) {
+                if (sLength < tLength) {
+                    return s.substring(i).equals(t.substring(i + 1));
+                } else if (sLength > tLength) {
+                    return s.substring(i + 1).equals(t.substring(i));
+                } else {
+                    return s.substring(i + 1).equals(t.substring(i + 1));
+                }
+            }
+        }
+        return Math.abs(sLength - tLength) == 1;
+    }
+
+    // Test
+    public static void main(String[] args) {
+        OneEditDistance solution = new OneEditDistance();
+
+        boolean output1 = solution.isOneEditDistance("ab", "acb");
+        System.out.println("Test 1 passed? " + (output1 == true));
+
+        boolean output2 = solution.isOneEditDistance("", "");
+        System.out.println("Test 2 passed? " + (output2 == false));
+    }
+}