leetcode分类-LeetCode-Java-Accepted:这是我的Java学习之旅

leetcode 分类LeetCode-Java-接受 这是 Leetcode 问题的 Java 解决方案。 细节 标题和答案格式 /* * 17. Letter Combinations of a Phone Number * Target: Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent. * Difficulty：Medium * Classification：String, Backtracking */ /* * Solution 1 * 2019-06-08 Runtime: 0 ms * Algorithm: => Recursive * If digits == "23", * first layer recursive: combination("a", "23", 1, ""), combination("b", "23", 1, ""), combination("