tasks a-s

Task/Queue-Usage/Go/queue-usage-1.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+    "fmt"
+    "queue"
+)
+
+func main() {
+    q := new(queue.Queue)
+    fmt.Println("empty?", q.Empty())
+
+    x := "black"
+    fmt.Println("push", x)
+    q.Push(x)
+
+    fmt.Println("empty?", q.Empty())
+    r, ok := q.Pop()
+    if ok {
+        fmt.Println(r, "popped")
+    } else {
+        fmt.Println("pop failed")
+    }
+
+    var n int
+    for _, x := range []string{"blue", "red", "green"} {
+        fmt.Println("pushing", x)
+        q.Push(x)
+        n++
+    }
+
+    for i := 0; i < n; i++ {
+        r, ok := q.Pop()
+        if ok {
+            fmt.Println(r, "popped")
+        } else {
+            fmt.Println("pop failed")
+        }
+    }
+}

Task/Queue-Usage/Go/queue-usage-2.go

@@ -0,0 +1,36 @@
+package main
+
+import "fmt"
+
+func main() {
+    q := make(chan string, 3)
+    fmt.Println("empty?", len(q) == 0)
+
+    x := "black"
+    fmt.Println("push", x)
+    q <- x
+
+    fmt.Println("empty?", len(q) == 0)
+    select {
+    case r := <-q:
+        fmt.Println(r, "popped")
+    default:
+        fmt.Println("pop failed")
+    }
+
+    var n int
+    for _, x := range []string{"blue", "red", "green"} {
+        fmt.Println("pushing", x)
+        q <- x
+        n++
+    }
+
+    for i := 0; i < n; i++ {
+        select {
+        case r := <-q:
+            fmt.Println(r, "popped")
+        default:
+            fmt.Println("pop failed")
+        }
+    }
+}

Task/Queue-Usage/Go/queue-usage-3.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+    "fmt"
+    "container/list"
+)
+
+func main() {
+    q := list.New()
+    fmt.Println("empty?", q.Len() == 0)
+
+    x := "black"
+    fmt.Println("push", x)
+    q.PushBack(x)
+
+    fmt.Println("empty?", q.Len() == 0)
+    if e := q.Front(); e != nil {
+        r := q.Remove(e)
+        fmt.Println(r, "popped")
+    } else {
+        fmt.Println("pop failed")
+    }
+
+    var n int
+    for _, x := range []string{"blue", "red", "green"} {
+        fmt.Println("pushing", x)
+        q.PushBack(x)
+        n++
+    }
+
+    for i := 0; i < n; i++ {
+        if e := q.Front(); e != nil {
+            r := q.Remove(e)
+            fmt.Println(r, "popped")
+        } else {
+            fmt.Println("pop failed")
+        }
+    }
+}