feat: add swift implementation to lcof2 problem: No.106 (#3619)

Author: klever34

lcof2/剑指 Offer II 106. 二分图/README.md

@@ -183,6 +183,36 @@ func isBipartite(graph [][]int) bool {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    private var parent: [Int] = []
+
+    func isBipartite(_ graph: [[Int]]) -> Bool {
+        let n = graph.count
+        parent = Array(0..<n)
+
+        for u in 0..<n {
+            for v in graph[u] {
+                if find(u) == find(v) {
+                    return false
+                }
+                parent[find(v)] = find(graph[u][0])
+            }
+        }
+        return true
+    }
+
+    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 106. 二分图/Solution.swift

@@ -0,0 +1,25 @@
+class Solution {
+    private var parent: [Int] = []
+
+    func isBipartite(_ graph: [[Int]]) -> Bool {
+        let n = graph.count
+        parent = Array(0..<n)
+
+        for u in 0..<n {
+            for v in graph[u] {
+                if find(u) == find(v) {
+                    return false
+                }
+                parent[find(v)] = find(graph[u][0])
+            }
+        }
+        return true
+    }
+
+    private func find(_ x: Int) -> Int {
+        if parent[x] != x {
+            parent[x] = find(parent[x])
+        }
+        return parent[x]
+    }
+}