Update 0459.重复的子字符串.md

problems/0459.重复的子字符串.md

@@ -421,5 +421,48 @@ function repeatedSubstringPattern(s: string): boolean {
 };
 ```
 
+
+Swift:
+
+> 前缀表统一减一
+```swift
+	func repeatedSubstringPattern(_ s: String) -> Bool {
+
+        let sArr = Array(s)
+        let len = s.count
+        if len == 0 {
+            return false
+        }
+        var next = Array.init(repeating: -1, count: len)
+
+        getNext(&next,sArr)
+
+        if next.last != -1 && len % (len - (next[len-1] + 1)) == 0{
+            return true
+        }
+
+        return false
+    }
+
+    func getNext(_ next: inout [Int], _ str:[Character]) {
+
+        var j = -1
+        next[0] = j
+
+        for i in 1 ..< str.count {
+
+            while j >= 0 && str[j+1] != str[i] {
+                j = next[j]
+            }
+
+            if str[i] == str[j+1] {
+                j += 1
+            }
+
+            next[i] = j
+        }
+    }
+```
+
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