[Create] LeetCode_859 BuddyString

Author: holmir97

BuddyString.java

@@ -0,0 +1,67 @@
+public class BuddyString {
+    public static void main(String[] args) {
+        System.out.println(new BuddyString().buddyStrings("aaaaaaabc","aaaaaaacb"));
+    }
+    public boolean buddyStrings(String a, String b) {
+        StringBuffer str1 = new StringBuffer(a);
+        StringBuffer str2 = new StringBuffer(b);
+        boolean flag = false;
+
+        int len = str1.length()>str2.length()? str1.length():str2.length();
+//        if(a.equals(b))
+//            return true;
+
+        for(int i = 0; i<len-1; i++){
+            try {
+                char tmp = ' ';
+                tmp = str2.charAt(i);
+                str2.replace(i,i+1,String.valueOf(str2.charAt(i+1)));
+                str2.replace(i+1,i+2,String.valueOf(tmp));
+
+                if(str1.toString().equals(str2.toString()))
+                    return flag = true;
+                else {
+                    tmp = str2.charAt(i);
+                    str2.replace(i,i+1,String.valueOf(str2.charAt(i+1)));
+                    str2.replace(i+1,i+2,String.valueOf(tmp));
+                }
+
+            }catch (IndexOutOfBoundsException e){
+                return false;
+            }
+        }
+        return flag;
+    }
+}
+
+/* O(N) 출처: LeetCode
+class Solution {
+    public boolean buddyStrings(String A, String B) {
+        if (A.length() != B.length()) return false;
+        if (A.equals(B)) {
+            int[] count = new int[26];
+            for (int i = 0; i < A.length(); ++i)
+                count[A.charAt(i) - 'a']++;
+
+            for (int c: count)
+                if (c > 1) return true;
+            return false;
+        } else {
+            int first = -1, second = -1;
+            for (int i = 0; i < A.length(); ++i) {
+                if (A.charAt(i) != B.charAt(i)) {
+                    if (first == -1)
+                        first = i;
+                    else if (second == -1)
+                        second = i;
+                    else
+                        return false;
+                }
+            }
+
+            return (second != -1 && A.charAt(first) == B.charAt(second) &&
+                    A.charAt(second) == B.charAt(first));
+        }
+    }
+}
+ */