coded + unit tested

Author: Ram swaroop

src/me/ramswaroop/arrays/ArrangeNosToFormBiggestNo.java

@@ -0,0 +1,47 @@
+package me.ramswaroop.arrays;
+
+import java.util.Arrays;
+import java.util.Comparator;
+
+/**
+ * Created by IntelliJ IDEA.
+ *
+ * @author: ramswaroop
+ * @date: 11/1/15
+ * @time: 8:53 PM
+ */
+public class ArrangeNosToFormBiggestNo {
+
+    /**
+     * Sorts no.s in array {@param a} such that if you form a number {@code n}
+     * by concatenating digits in order a[0]....a[size], it results being the
+     * largest number possible.
+     * <p/>
+     * For example,
+     * I/P: {54, 546, 548, 60}
+     * O/P: {60, 548, 546, 54} i.e, 6054854654
+     * <p/>
+     * I/P: {1, 34, 3, 98, 9, 76, 45, 4}
+     * O/P: {9, 98, 76, 45, 4, 34, 3, 1} i.e, 998764543431
+     *
+     * @param a
+     * @return
+     */
+    public static Integer[] arrangeArrayOfNosToFormBiggestNo(Integer[] a) {
+
+        Arrays.sort(a, new Comparator<Integer>() {
+            @Override
+            public int compare(Integer o1, Integer o2) {
+                return Integer.parseInt(o1 + "" + o2) > Integer.parseInt(o2 + "" + o1) ? -1 : 1;
+            }
+        });
+
+        return a;
+    }
+
+    public static void main(String a[]) {
+        System.out.println(Arrays.toString(arrangeArrayOfNosToFormBiggestNo(new Integer[]{45, 567, 12, 1})));
+        System.out.println(Arrays.toString(arrangeArrayOfNosToFormBiggestNo(new Integer[]{54, 546, 548, 60})));
+        System.out.println(Arrays.toString(arrangeArrayOfNosToFormBiggestNo(new Integer[]{1, 34, 3, 98, 9, 76, 45, 4})));
+    }
+}