Definition 1 (Subsequence) Let (an)n be a sequence and (kn)n ⊂ N be a strictly increasing. sequence of natural numbers. Then the sequence (akn )n is called a subsequence of (an)n. Idea: This means that asubsequence can skip values of theoriginal sequence (an)n, but can. never...
Swift 5 通过给BinaryInteger添加了isMultiple(of:)方法简化了这一操作SE-0225: iffirstNumber.isMultiple(of: secondNumber) {print("\(secondNumber)*\(firstNumber/secondNumber)=\(firstNumber)") } 即使你传入 0 作为参数,isMultiple(of:)依然可以工作,而且是代码更加简洁明了。 Escaping Raw Strings Swift ...