Added Question 1_2

java/Chapter 1/Question1_2/Question1_2.java

@@ -0,0 +1,63 @@
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+package question1_2;
+
+/**
+ *
+ * @author albertovega
+ */
+public class Question1_2 {
+
+    public static String sort(String s) {
+        char[] content = s.toCharArray();
+        java.util.Arrays.sort(content);
+        return new String(content);
+    }
+
+    public static boolean permutation(String s, String t) {
+        if (s.length() != t.length()) {
+            return false;
+        }
+        return sort(s).equals(sort(t));
+    }
+    public static boolean permutation2(String s, String t) {
+        if (s.length() != t.length()) {
+            return false;
+        }
+        int[] letters = new int[128]; // Asumption
+
+        char[] s_array = s.toCharArray();
+        for (char c : s_array) { // count  number of each char in s.
+         letters[c]++;
+        }
+
+        for (int i = 0; i < t.length(); i++) {
+            int c = (int) t.charAt(i);
+            letters[c]--;
+            if(letters[c] < 0) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    /**
+     * @param args the command line arguments
+     */
+    public static void main(String[] args) {
+        String string1 = "dog";
+        String string2 = "god";
+
+       boolean result; 
+       result = permutation(string1, string2);
+       System.out.println(result);
+       boolean result2;
+       result2 = permutation2(string1, string2);
+       System.out.println(result2);
+
+
+    }   
+}