Java, Data Structures, Arraylist, Set, Hashmap.
Integer> map1 = new HashMap<>(); map1.put("foo", 1); map1.put("bar", 2); list.add(map1); Map<String, Integer> map2 = new HashMap<>(); map2.put("baz", 3); list.add(map2); Map<String, Integer> map = new HashMap<>(); for (Map<String, Integer> m : list) { for (Map.Entry<String, Integer> entry :