diff --git a/codes/swift/Package.resolved b/codes/swift/Package.resolved new file mode 100644 index 000000000..159c83d26 --- /dev/null +++ b/codes/swift/Package.resolved @@ -0,0 +1,14 @@ +{ + "pins" : [ + { + "identity" : "swift-collections", + "kind" : "remoteSourceControl", + "location" : "https://github.com/apple/swift-collections", + "state" : { + "branch" : "release/1.1", + "revision" : "4a1d92ba85027010d2c528c05576cde9a362254b" + } + } + ], + "version" : 2 +} diff --git a/codes/swift/Package.swift b/codes/swift/Package.swift index ba293d40d..7f67d18a2 100644 --- a/codes/swift/Package.swift +++ b/codes/swift/Package.swift @@ -99,6 +99,9 @@ let package = Package( .executable(name: "max_capacity", targets: ["max_capacity"]), .executable(name: "max_product_cutting", targets: ["max_product_cutting"]), ], + dependencies: [ + .package(url: "https://github.com/apple/swift-collections", branch: "release/1.1"), + ], targets: [ // helper .target(name: "utils", path: "utils"), @@ -141,7 +144,7 @@ let package = Package( .executableTarget(name: "avl_tree", dependencies: ["utils"], path: "chapter_tree", sources: ["avl_tree.swift"]), // chapter_heap .executableTarget(name: "my_heap", dependencies: ["utils"], path: "chapter_heap", sources: ["my_heap.swift"]), - .executableTarget(name: "top_k", dependencies: ["utils"], path: "chapter_heap", sources: ["top_k.swift"]), + .executableTarget(name: "top_k", dependencies: ["utils", .product(name: "HeapModule", package: "swift-collections")], path: "chapter_heap", sources: ["top_k.swift"]), // chapter_graph .executableTarget(name: "graph_adjacency_matrix", dependencies: ["utils"], path: "chapter_graph", sources: ["graph_adjacency_matrix.swift"]), .executableTarget(name: "graph_adjacency_list", dependencies: ["utils"], path: "chapter_graph", sources: ["graph_adjacency_list.swift"]), diff --git a/codes/swift/chapter_heap/top_k.swift b/codes/swift/chapter_heap/top_k.swift index eda64ab9b..da81a31fb 100644 --- a/codes/swift/chapter_heap/top_k.swift +++ b/codes/swift/chapter_heap/top_k.swift @@ -4,21 +4,22 @@ * Author: nuomi1 (nuomi1@qq.com) */ +import HeapModule import utils /* 基于堆查找数组中最大的 k 个元素 */ func topKHeap(nums: [Int], k: Int) -> [Int] { // 将数组的前 k 个元素入堆 - var heap = Array(nums.prefix(k)) + var heap = Heap(nums.prefix(k)) // 从第 k+1 个元素开始,保持堆的长度为 k for i in stride(from: k, to: nums.count, by: 1) { // 若当前元素大于堆顶元素,则将堆顶元素出堆、当前元素入堆 - if nums[i] > heap.first! { - heap.removeFirst() - heap.insert(nums[i], at: 0) + if nums[i] > heap.min()! { + _ = heap.removeMin() + heap.insert(nums[i]) } } - return heap + return heap.unordered } @main diff --git a/codes/swift/chapter_sorting/merge_sort.swift b/codes/swift/chapter_sorting/merge_sort.swift index 7dadedd37..75ddf71a0 100644 --- a/codes/swift/chapter_sorting/merge_sort.swift +++ b/codes/swift/chapter_sorting/merge_sort.swift @@ -5,38 +5,39 @@ */ /* 合并左子数组和右子数组 */ -// 左子数组区间 [left, mid] -// 右子数组区间 [mid + 1, right] func merge(nums: inout [Int], left: Int, mid: Int, right: Int) { - // 初始化辅助数组 - let tmp = Array(nums[left ..< (right + 1)]) - // 左子数组的起始索引和结束索引 - let leftStart = left - left - let leftEnd = mid - left - // 右子数组的起始索引和结束索引 - let rightStart = mid + 1 - left - let rightEnd = right - left - // i, j 分别指向左子数组、右子数组的首元素 - var i = leftStart - var j = rightStart - // 通过覆盖原数组 nums 来合并左子数组和右子数组 - for k in left ... right { - // 若“左子数组已全部合并完”,则选取右子数组元素,并且 j++ - if i > leftEnd { - nums[k] = tmp[j] - j += 1 - } - // 否则,若“右子数组已全部合并完”或“左子数组元素 <= 右子数组元素”,则选取左子数组元素,并且 i++ - else if j > rightEnd || tmp[i] <= tmp[j] { - nums[k] = tmp[i] + // 左子数组区间 [left, mid], 右子数组区间 [mid+1, right] + // 创建一个临时数组 tmp ,用于存放合并后的结果 + var tmp = Array(repeating: 0, count: right - left + 1) + // 初始化左子数组和右子数组的起始索引 + var i = left, j = mid + 1, k = 0 + // 当左右子数组都还有元素时,比较并将较小的元素复制到临时数组中 + while i <= mid, j <= right { + if nums[i] <= nums[j] { + tmp[k] = nums[i] i += 1 - } - // 否则,若“左右子数组都未全部合并完”且“左子数组元素 > 右子数组元素”,则选取右子数组元素,并且 j++ - else { - nums[k] = tmp[j] + k += 1 + } else { + tmp[k] = nums[j] j += 1 + k += 1 } } + // 将左子数组和右子数组的剩余元素复制到临时数组中 + while i <= mid { + tmp[k] = nums[i] + i += 1 + k += 1 + } + while j <= right { + tmp[k] = nums[j] + j += 1 + k += 1 + } + // 将临时数组 tmp 中的元素复制回原数组 nums 的对应区间 + for k in tmp.indices { + nums[left + k] = tmp[k] + } } /* 归并排序 */