newList.addAll(list1); Collections.sort(newList)

Week 3: Objects, files and exceptions/8. Combine lists

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+Write the method
+
+ArrayList<Integer> combine(ArrayList<Integer> list1, ArrayList<Integer> list2)
+
+which takes as parameters two lists of integers. 
+The lists are ordered in ascending order (i.e. the smallest number is first and the largest last).
+
+The method returns a new list of integer type with all the elements of the parameter lists combined.
+In the new list, the elements are also ordered in order of magnitude.
+
+
+
+Example method call:
+public static void main(String[] args){
+    ArrayList<Integer> list1 = new ArrayList<>();
+    list1.add(1);
+    list1.add(3);
+    list1.add(5);
+
+    ArrayList<Integer> list2 = new ArrayList<>();
+    list2.add(2);
+    list2.add(4);
+    list2.add(6);
+
+    ArrayList<Integer> combined = combine(list1, list2);
+
+    System.out.println(combined);
+}
+Program outputs:
+[1, 2, 3, 4, 5, 6]
+
+
+
+======================================
+
+
+
+import java.util.Random;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+
+public class Test{
+    public static void main(String[] args){
+        final Random r = new Random();
+        
+        testaa(new int[]{1,3,5,7,9}, new int[]{2,4,6,8,10});
+        testaa(new int[]{10,20,30,40,50,60}, new int[]{70,80,90,100,110});
+        testaa(new int[]{1,11,21,31,41}, new int[]{2,3,4,32,33,34,42});
+
+        
+        
+    }
+    
+    public static void tulosta(ArrayList<String> lista) {
+        System.out.print("[\"");
+        System.out.print(String.join("\", \"", lista));
+        System.out.println("\"]");
+    }
+    
+    public static void testaa(int[] l1, int[] l2) {
+        ArrayList<Integer> lista1 = new ArrayList<>();
+        for (int a : l1) {
+            lista1.add(a);
+        }
+        
+        ArrayList<Integer> lista2 = new ArrayList<>();
+        for (int a : l2) {
+            lista2.add(a);
+        }
+        
+        System.out.println("Testing with lists ");
+        System.out.println("" + lista1);
+        System.out.println("" + lista2);
+        System.out.println("Combined: ");
+        System.out.println(combine(lista1, lista2));
+        System.out.println("");
+    }
+    
+    
+    
+
+
+    // https://stackoverflow.com/a/189569/5324726
+    // combine used by testaa
+    public static ArrayList<Integer> combine(ArrayList<Integer> list1, ArrayList<Integer> list2){
+        ArrayList<Integer> combined = new ArrayList<>();
+        // for (int a : list1) {
+        //     combined.add(a);
+        // }
+        // for (int a : list2) {
+        //     combined.add(a);
+        // }
+
+        combined.addAll(list1);
+        combined.addAll(list2);
+        Collections.sort(combined);
+        return combined;
+    }
+
+
+
+
+}
+
+
+
+
+
+Testing with lists 
+[1, 3, 5, 7, 9]
+[2, 4, 6, 8, 10]
+Combined: 
+[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
+
+Testing with lists 
+[10, 20, 30, 40, 50, 60]
+[70, 80, 90, 100, 110]
+Combined: 
+[10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110]
+
+Testing with lists 
+[1, 11, 21, 31, 41]
+[2, 3, 4, 32, 33, 34, 42]
+Combined: 
+[1, 2, 3, 4, 11, 21, 31, 32, 33, 34, 41, 42]
+
+
+