作为框架包含时,与其他框架一样导入它
import PriorityQueue
优先队列被定义为泛型并使用比较回调初始化,如PriorityQueue<T>((T, T) -> Bool)
。例如,它可以像这样操作字符:
var characters = PriorityQueue<Character>(<)
characters.push("C")
characters.push("B")
characters.push("A")
println("Characters:")
for p in characters {
println(" * \(p)")
}
println()
这将打印
* A
* B
* C
更实际的用例将操作结构体或类,如这样
struct Node {
let priority: Int
}
var nodes = PriorityQueue<Node>({ $0.priority < $1.priority })
nodes.push(Node(priority: 4))
nodes.push(Node(priority: 5))
nodes.push(Node(priority: 3))
nodes.push(Node(priority: 1))
println("Nodes:")
for node in nodes {
println(" * Node(priority: \(node.priority))")
}
println()
这将打印
Nodes:
* Node(priority: 1)
* Node(priority: 3)
* Node(priority: 4)
* Node(priority: 5)
var ints = PriorityQueue<Int>(<)
ints.push(3)
ints.remove(3) // Returns 3
ints.remove(3) // Returns nil
ints.push(5)
ints.push(4)
ints.heap // Returns [4, 5]
使用以下命令重建此Playground
rm -rf README.playground/
playground README.md --platform ios