2016 Update

Task/Set/Go/set-3.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+    "fmt"
+
+    "golang.org/x/tools/container/intsets"
+)
+
+func main() {
+    var s0, s1 intsets.Sparse // create some empty sets
+    s1.Insert(3)              // insert an element
+    s2 := newSet(3, 1)        // create sets with elements
+    s3 := newSet(3, 1, 4, 1, 5, 9)
+
+    // output
+    fmt.Println("s0:", &s0)
+    fmt.Println("s1:", &s1)
+    fmt.Println("s2:", s2)
+    fmt.Println("s3:", s3)
+
+    // element predicate
+    fmt.Printf("%v ∈ s0: %t\n", 3, s0.Has(3))
+    fmt.Printf("%v ∈ s3: %t\n", 3, s3.Has(3))
+    fmt.Printf("%v ∈ s3: %t\n", 2, s3.Has(2))
+
+    // union
+    b := newSet(4, 2)
+    var s intsets.Sparse
+    s.Union(s3, b)
+    fmt.Printf("s3 ∪ %v: %v\n", b, &s)
+
+    // intersection
+    s.Intersection(s3, b)
+    fmt.Printf("s3 ∩ %v: %v\n", b, &s)
+
+    // difference
+    s.Difference(s3, b)
+    fmt.Printf("s3 \\ %v: %v\n", b, &s)
+
+    // subset predicate
+    fmt.Printf("%v ⊆ s3: %t\n", b, b.SubsetOf(s3))
+    fmt.Printf("%v ⊆ s3: %t\n", s2, s2.SubsetOf(s3))
+    fmt.Printf("%v ⊆ s3: %t\n", &s0, s0.SubsetOf(s3))
+
+    // equality
+    s2Same := newSet(1, 3)
+    fmt.Printf("%v = s2: %t\n", s2Same, s2Same.Equals(s2))
+
+    // delete
+    s3.Remove(3)
+    fmt.Println("s3, 3 removed:", s3)
+}
+
+func newSet(ms ...int) *intsets.Sparse {
+    var set intsets.Sparse
+    for _, m := range ms {
+        set.Insert(m)
+    }
+    return &set
+}