guava中集合（set）的算法和操作

 

 

static void intersection() {
    Set<Integer> set1 = Sets.newHashSet(1, 2);
    Set<Integer> set2 = Sets.newHashSet(2, 3);
    Set<Integer> intersectionSet = Sets.newHashSet();
    Set<Integer> unionSet = Sets.newHashSet();
    Set<Integer> differenceSet1AndSet2 = Sets.newHashSet();
    Set<Integer> differenceSet2AndSet1 = Sets.newHashSet();
    Set<Integer> symmetricDifferenceSet = Sets.newHashSet();
    Sets.intersection(set1, set2).copyInto(intersectionSet);
    Sets.union(set1, set2).copyInto(unionSet);
    Sets.difference(set1, set2).copyInto(differenceSet1AndSet2);
    Sets.difference(set2, set1).copyInto(differenceSet2AndSet1);
    Sets.symmetricDifference(set1, set2).copyInto(symmetricDifferenceSet);
    Set<List<Integer>> cartesianProduct = Sets.cartesianProduct(set1, set2);
    Set<Set<Integer>> powerSet = Sets.powerSet(set1);
    Set<Set<Integer>> combinationsSet = Sets.combinations(unionSet, 2);
    // output
    System.out.println(String.format("set1:%s", set1));
    // set1:[1, 2]

    System.out.println(String.format("set2:%s", set2));
    // set2:[2, 3]

    System.out.println(String.format("intersectionSet:%s", intersectionSet));
    // intersectionSet:[2]

    System.out.println(String.format("unionSet:%s", unionSet));
    // unionSet:[1, 2, 3]

    System.out.println(String.format("differenceSet1AndSet2:%s", differenceSet1AndSet2));
    // differenceSet1AndSet2:[1]

    System.out.println(String.format("differenceSet2AndSet1:%s", differenceSet2AndSet1));
    // differenceSet2AndSet1:[3]

    System.out.println(String.format("symmetricDifferenceSet:%s", symmetricDifferenceSet));
    // symmetricDifferenceSet:[1, 3]

    System.out.println(String.format("cartesianProduct:%s", cartesianProduct));
    // cartesianProduct:[[1, 2], [1, 3], [2, 2], [2, 3]]

    System.out.println(String.format("powerSet:%s", powerSet.stream().map(s -> {
        // powerSet:[[], [1], [2], [1, 2]]
        return s.toString();
    }).collect(Collectors.toList())));

    System.out.println(String.format("combinationsSet:%s", combinationsSet.stream().map(s -> {
        // combinationsSet:[[1, 2], [1, 3], [2, 3]]
        return s.toString();
    }).collect(Collectors.toList())));
}