Added check permutation

Author: rampatra

src/main/java/com/ctci/arraysandstrings/CheckPermutation.java

@@ -0,0 +1,53 @@
+package com.ctci.arraysandstrings;
+
+import java.util.Arrays;
+
+/**
+ * @author rampatra
+ * @since 19/11/2018
+ */
+public class CheckPermutation {
+
+    private static boolean isOnePermutationOfOther(String s1, String s2) {
+        if (s1.length() != s2.length()) {
+            return false;
+        }
+
+        char[] c1 = s1.toCharArray();
+        char[] c2 = s2.toCharArray();
+        Arrays.sort(c1);
+        Arrays.sort(c2);
+
+        return Arrays.equals(c1, c2);
+    }
+
+    private static boolean isOnePermutationOfOtherGivenThatStringsContainOnlyAscii(String s1, String s2) {
+        if (s1.length() != s2.length()) {
+            return false;
+        }
+
+        int[] chars = new int[128]; // assuming strings contain only ASCII characters
+
+        for (int i = 0; i < s1.length(); i++) {
+            chars[s1.charAt(i)]++;
+        }
+
+        for (int i = 0; i < s2.length(); i++) {
+            chars[s2.charAt(i)]--;
+            if (chars[s2.charAt(i)] < 0) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    public static void main(String[] args) {
+        System.out.println(isOnePermutationOfOther("ram", "mar"));
+        System.out.println(isOnePermutationOfOther("rama", "mar"));
+        System.out.println(isOnePermutationOfOther("rama", "marA"));
+        System.out.println("-------");
+        System.out.println(isOnePermutationOfOtherGivenThatStringsContainOnlyAscii("ram", "mar"));
+        System.out.println(isOnePermutationOfOtherGivenThatStringsContainOnlyAscii("rama", "mar"));
+        System.out.println(isOnePermutationOfOtherGivenThatStringsContainOnlyAscii("rama", "marA"));
+    }
+}

src/main/java/com/rampatra/ctci/IsUnique.java renamed to src/main/java/com/ctci/arraysandstrings/IsUnique.java

@@ -1,4 +1,4 @@
-package com.rampatra.ctci;
+package com.ctci.arraysandstrings;
 
 /**
  * @author rampatra