feat: add swift implementation to lcof2 problem: No.117

lcof2/剑指 Offer II 117. 相似的字符串/README.md

@@ -208,6 +208,58 @@ func numSimilarGroups(strs []string) int {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    private var parent: [Int] = []
+
+    func numSimilarGroups(_ strs: [String]) -> Int {
+        let n = strs.count
+        parent = Array(0..<n)
+
+        for i in 0..<n {
+            for j in (i + 1)..<n {
+                if check(strs[i], strs[j]) {
+                    parent[find(i)] = find(j)
+                }
+            }
+        }
+
+        var groups = 0
+        for i in 0..<n {
+            if i == find(i) {
+                groups += 1
+            }
+        }
+        return groups
+    }
+
+    private func check(_ a: String, _ b: String) -> Bool {
+        let n = a.count
+        var count = 0
+        let arrA = Array(a), arrB = Array(b)
+
+        for i in 0..<n {
+            if arrA[i] != arrB[i] {
+                count += 1
+            }
+            if count > 2 {
+                return false
+            }
+        }
+        return count <= 2
+    }
+
+    private func find(_ x: Int) -> Int {
+        if parent[x] != x {
+            parent[x] = find(parent[x])
+        }
+        return parent[x]
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 117. 相似的字符串/Solution.swift

@@ -0,0 +1,47 @@
+class Solution {
+    private var parent: [Int] = []
+
+    func numSimilarGroups(_ strs: [String]) -> Int {
+        let n = strs.count
+        parent = Array(0..<n)
+
+        for i in 0..<n {
+            for j in (i + 1)..<n {
+                if check(strs[i], strs[j]) {
+                    parent[find(i)] = find(j)
+                }
+            }
+        }
+
+        var groups = 0
+        for i in 0..<n {
+            if i == find(i) {
+                groups += 1
+            }
+        }
+        return groups
+    }
+
+    private func check(_ a: String, _ b: String) -> Bool {
+        let n = a.count
+        var count = 0
+        let arrA = Array(a), arrB = Array(b)
+
+        for i in 0..<n {
+            if arrA[i] != arrB[i] {
+                count += 1
+            }
+            if count > 2 {
+                return false
+            }
+        }
+        return count <= 2
+    }
+
+    private func find(_ x: Int) -> Int {
+        if parent[x] != x {
+            parent[x] = find(parent[x])
+        }
+        return parent[x]
+    }
+}