refactor 161

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_161.java

@@ -1,48 +1,71 @@
 package com.fishercoder.solutions;
 
-/**Given two strings S and T, determine if they are both one edit distance apart.*/
+/**
+ * 161. One Edit Distance
+ *
+ * Given two strings s and t, determine if they are both one edit distance apart.
+ *
+ * Note:
+ *
+ * There are 3 possiblities to satisify one edit distance apart:
+ *
+ *     Insert a character into s to get t
+ *     Delete a character from s to get t
+ *     Replace a character of s to get t
+ *
+ * Example 1:
+ * Input: s = "ab", t = "acb"
+ * Output: true
+ * Explanation: We can insert 'c' into s to get t.
+ *
+ * Example 2:
+ * Input: s = "cab", t = "ad"
+ * Output: false
+ * Explanation: We cannot get t from s by only one step.
+ *
+ * Example 3:
+ * Input: s = "1203", t = "1213"
+ * Output: true
+ * Explanation: We can replace '0' with '1' to get t.
+ */
 public class _161 {
+  public static class Solution1 {
+    public boolean isOneEditDistance(String s, String t) {
+      char[] schar = s.toCharArray();
+      char[] tchar = t.toCharArray();
 
-    public static boolean isOneEditDistance(String s, String t) {
-        char[] schar = s.toCharArray();
-        char[] tchar = t.toCharArray();
+      if (Math.abs(s.length() - t.length()) == 1) {
+        char[] longer = (s.length() > t.length()) ? schar : tchar;
+        char[] shorter = (longer == schar) ? tchar : schar;
 
-        if (Math.abs(s.length() - t.length()) == 1) {
-            char[] longer = (s.length() > t.length()) ? schar : tchar;
-            char[] shorter = (longer == schar) ? tchar : schar;
-
-            int diffCnt = 0;
-            int i = 0;
-            int j = 0;
-            for (; i < shorter.length && j < longer.length; ) {
-                if (longer[j] != shorter[i]) {
-                    diffCnt++;
-                    j++;
-                } else {
-                    i++;
-                    j++;
-                }
-            }
-            return diffCnt == 1 || diffCnt == 0;//it could be the last char of the longer is the different one, in that case, diffCnt remains to be zero
-        } else if (s.length() == t.length()) {
-            int diffCnt = 0;
-            for (int i = 0; i < s.length(); i++) {
-                if (schar[i] != tchar[i]) {
-                    diffCnt++;
-                }
-                if (diffCnt > 1) {
-                    return false;
-                }
-            }
-            return diffCnt == 1;
+        int diffCnt = 0;
+        int i = 0;
+        int j = 0;
+        for (; i < shorter.length && j < longer.length; ) {
+          if (longer[j] != shorter[i]) {
+            diffCnt++;
+            j++;
+          } else {
+            i++;
+            j++;
+          }
         }
-        return false;
-    }
-
-    public static void main(String... strings) {
-        String s = "a";
-        String t = "ac";
-        System.out.println(isOneEditDistance(s, t));
+        return diffCnt == 1
+            || diffCnt
+            == 0;//it could be the last char of the longer is the different one, in that case, diffCnt remains to be zero
+      } else if (s.length() == t.length()) {
+        int diffCnt = 0;
+        for (int i = 0; i < s.length(); i++) {
+          if (schar[i] != tchar[i]) {
+            diffCnt++;
+          }
+          if (diffCnt > 1) {
+            return false;
+          }
+        }
+        return diffCnt == 1;
+      }
+      return false;
     }
-
+  }
 }

src/test/java/com/fishercoder/_161Test.java

@@ -0,0 +1,21 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._161;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class _161Test {
+  private static _161.Solution1 solution1;
+
+  @BeforeClass
+  public static void setup() {
+    solution1 = new _161.Solution1();
+  }
+
+  @Test
+  public void test1() {
+    assertEquals(true, solution1.isOneEditDistance("a", "ac"));
+  }
+}