上一篇你真的会用String吗(3)-关于字符串拼接中我们提到了String.intern()方法,本篇我们就来详细的看下这个方法是干嘛的.首先来看下jdk8中这个方法的注释: When the intern method is invoked, if the pool already contains a string equal to this String object as determined by the equals(Object) method, then the string
Given a collection of numbers that might contain duplicates, return all possible unique permutations. Example: Input: [1,1,2] Output: [ [1,1,2], [1,2,1], [2,1,1] ] 法1.递归.swap.回溯.唯一要多做的就是去重.用unordered_set的insert就行.因为用的是hash的无序集合,所以要用std::sort重排一下. 细节:
题目要求:去除,和.,相同的单词去除后面的.区分大小写 示例:输入:There is a will,there is a way. 输出There is a will there way 答案代码: String s = "There is a will there is a way"; Pattern p = Pattern.compile("[,.]"); String ss = p.matcher(s).replaceAll(""); L