feat: add swift implementation to lcp problem: No.24 (#3773)

Author: klever34

lcp/LCP 24. 数字游戏/README.md

@@ -307,6 +307,81 @@ func (h *hp) Pop() any {
 }
 ```
 
+#### Swift
+
+```swift
+class MedianFinder {
+    private var lowerHeap: [Int] = []
+    private var upperHeap: [Int] = []
+    private let mod = 1_000_000_007
+    private var sumLower = 0
+    private var sumUpper = 0
+
+    init() {}
+
+    func addNum(_ num: Int) {
+    
+        upperHeap.append(num)
+        sumUpper += num
+        upperHeap.sort()
+
+    
+        if let minUpper = upperHeap.first {
+            upperHeap.removeFirst()
+            lowerHeap.append(minUpper)
+            sumUpper -= minUpper
+            sumLower += minUpper
+            lowerHeap.sort(by: >)
+        }
+
+    
+        if lowerHeap.count > upperHeap.count + 1 {
+            if let maxLower = lowerHeap.first {
+                lowerHeap.removeFirst()
+                upperHeap.append(maxLower)
+                sumLower -= maxLower
+                sumUpper += maxLower
+                upperHeap.sort()
+            }
+        }
+    }
+
+    func findMedian() -> Int {
+        if lowerHeap.count > upperHeap.count {
+            return lowerHeap.first ?? 0
+        } else if let minUpper = upperHeap.first, let maxLower = lowerHeap.first {
+            return (minUpper + maxLower) / 2
+        }
+        return 0
+    }
+
+    func cal() -> Int {
+        let median = findMedian()
+        var result = (sumUpper - median * upperHeap.count) + (median * lowerHeap.count - sumLower)
+        result %= mod
+        if result < 0 {
+            result += mod
+        }
+        return Int(result)
+    }
+}
+
+class Solution {
+    func numsGame(_ nums: [Int]) -> [Int] {
+        let n = nums.count
+        var result = [Int]()
+        let finder = MedianFinder()
+
+        for i in 0..<n {
+            finder.addNum(nums[i] - i)
+            result.append(finder.cal())
+        }
+
+        return result
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcp/LCP 24. 数字游戏/Solution.swift

@@ -0,0 +1,70 @@
+class MedianFinder {
+    private var lowerHeap: [Int] = []
+    private var upperHeap: [Int] = []
+    private let mod = 1_000_000_007
+    private var sumLower = 0
+    private var sumUpper = 0
+
+    init() {}
+
+    func addNum(_ num: Int) {
+    
+        upperHeap.append(num)
+        sumUpper += num
+        upperHeap.sort()
+
+    
+        if let minUpper = upperHeap.first {
+            upperHeap.removeFirst()
+            lowerHeap.append(minUpper)
+            sumUpper -= minUpper
+            sumLower += minUpper
+            lowerHeap.sort(by: >)
+        }
+
+    
+        if lowerHeap.count > upperHeap.count + 1 {
+            if let maxLower = lowerHeap.first {
+                lowerHeap.removeFirst()
+                upperHeap.append(maxLower)
+                sumLower -= maxLower
+                sumUpper += maxLower
+                upperHeap.sort()
+            }
+        }
+    }
+
+    func findMedian() -> Int {
+        if lowerHeap.count > upperHeap.count {
+            return lowerHeap.first ?? 0
+        } else if let minUpper = upperHeap.first, let maxLower = lowerHeap.first {
+            return (minUpper + maxLower) / 2
+        }
+        return 0
+    }
+
+    func cal() -> Int {
+        let median = findMedian()
+        var result = (sumUpper - median * upperHeap.count) + (median * lowerHeap.count - sumLower)
+        result %= mod
+        if result < 0 {
+            result += mod
+        }
+        return Int(result)
+    }
+}
+
+class Solution {
+    func numsGame(_ nums: [Int]) -> [Int] {
+        let n = nums.count
+        var result = [Int]()
+        let finder = MedianFinder()
+
+        for i in 0..<n {
+            finder.addNum(nums[i] - i)
+            result.append(finder.cal())
+        }
+
+        return result
+    }
+}