Merge pull request #68 from AllanWell/master

sort of Swift

Author: wangzheng0822

swift/11_sorts/Sorts.swift

@@ -0,0 +1,81 @@
+import Foundation
+
+/// 冒泡排序
+///
+/// - Parameter elements: 数组
+/// - Returns: 返回值
+public func bubbleSort<T>(_ elements: [T]) ->[T] where T: Comparable {
+    var array = elements
+    guard array.count > 1 else {
+        return array
+    }
+    for i in 0..<array.count {
+        // 提前退出标志位
+        var flag = false
+        for j in 0..<array.count - i - 1 {
+            if array[j] > array[j+1] {
+                array.swapAt(j+1, j)
+                // 此次冒泡有数据交换
+                flag = true
+            }
+        }
+        if (!flag) {
+            break
+        }
+    }
+    return array
+}
+
+
+/// 插入排序
+///
+/// - Parameter elements: 数组
+/// - Returns: 返回值
+public func insertionSort<T>(_ elements: [T]) -> [T] where T: Comparable {
+    var array = elements
+    guard array.count > 1 else {
+        return array
+    }
+    for i in 1..<array.count {
+        let value = array[i]
+        var j = i - 1;
+        // 查找要插入的位置并移动数据
+        for p in (0...j).reversed() {
+            j = p
+            if array[p] > value {
+                array[p+1] = array[p]
+            } else {
+                break
+            }
+        }
+        array[j+1] = value
+    }
+    return array
+}
+
+
+/// 选择排序
+///
+/// - Parameter elements: 数组
+/// - Returns: 返回值
+public func selectionSort<T>(_ elements: [T]) -> [T] where T: Comparable {
+    var array = elements
+    guard array.count > 1 else {
+        return array
+    }
+    for i in 0..<array.count {
+        // 查找最小值
+        var minIndex = i
+        var minValue = array[i]
+        for j in i..<array.count {
+            if array[j] < minValue {
+                minValue = array[j]
+                minIndex = j
+            }
+        }
+        // 交换
+        array.swapAt(i, minIndex)
+    }
+    return array
+}
+