題目:給定兩個(gè)字符串a(chǎn)和b，判斷字符串b是否是由a字符串旋轉(zhuǎn)而成.

核心代碼:
<pre><code>` func isRotation(orginal:String,rotation:String) -> Bool {

    let len:Int = orginal.characters.count
    
    if len > 0 && len == rotation.characters.count {
        let mergeStr:String = orginal + orginal
        return mergeStr.contains(rotation)
    }
    return false
}

`</code></pre>

測(cè)試代碼:
<pre><code>var originalStr:String = "FlyElephant" var rotationStr:String = "antFlyEleph" var result:Bool = myString.isRotation(orginal: originalStr, rotation: rotationStr) print("\(rotationStr)是\(originalStr)的結(jié)果\(result)")</code></pre>