面试常见编程题汇总包含快排，二分查找

# Algorithm 数据结构和算法 package com.unisinsight.test; import lombok.AllArgsConstructor; import lombok.Data; import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.stream.Collectors; /** * TODO description * * @author 邹桔林 [[email protected]] * @date 2019/07/17 16:04 * @since 1.0 */ @Data @AllArgsConstructor public class Main { private int id; private String s1; public static void main(String args[]) { List<Integer> list = new ArrayList<>(); list.add(1); list.add(4); list.add(3); List<Integer> l1 = new ArrayList<>(); list.stream().filter(e -> e != 2).sorted().forEach(e -> { e = e + 1; l1.add(e); }); List<Integer> l2 = list.stream().map(e -> e * 2).filter(e -> e < 5).collect(Collectors.toList());//list每个元素*2 System.out.println(l1.get(2)); l2.forEach(System.out::println); l2.forEach(Test::tt); int i = (int) list.stream().map(Test::t2).filter(Test::check).count(); List<Main> l = new ArrayList<>(); Main main = new Main(1, "x1"); Main m1 = new Main(2, "x2"); l.add(main); l.add(m1); // Map<Integer, Student> map = list.stream().collect(Collectors.toMap(Student::getId, student -> student)); Map<Integer, Main> map = l.stream().collect(Collectors.toMap(Main::getId, e -> e)); Map<Integer, List<Main>> map2 =l.stream().collect(Collectors.groupingBy(Main::getId)); map.forEach((key, value) -> System.out.printf("key是%s，value是%s", key, value)); System.out.println(); map2.forEach((key,value)->{ System.out.println("key="+key); System.out.println("value="+value); }); } }