17. 电话号码的字母组合 - 力扣(LeetCode) 思路 回溯法 func letterCombinations(digits string) []string { if len(digits) == 0 || len(digits) > 4 { return nil } strMap := [10]string{ "", "", "abc", "def", &quo
import com.sun.jmx.remote.internal.ArrayQueue; import org.junit.Test; import java.util.*; import java.util.function.Supplier; import java.util.stream.Collectors; public class KS20220107_1 { public static void main(String[] args) { // Stack Deque&l