✨ que red package

datastructure/src/main/java/org/alis/smallcc/algorithm/leetcode/LeetCode16.java

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+package org.alis.smallcc.algorithm.leetcode;
+
+import java.util.Arrays;
+import java.util.concurrent.ThreadLocalRandom;
+
+/**
+ * 动态规划
+ * house-robber
+ * 小偷偷钱问题
+ * 现在有一个排别墅 小偷可以去偷钱，每一栋别墅里面的钱的数量都不一样，但是没两个邻居之间有报警装置，小偷不能偷挨在一起的别墅，请问最坏的情况下小偷能偷多少
+ * <p>
+ * 例如： [1,2,2,4,1,2,3] 小偷偷到的钱= 4+3+2
+ *
+ * @author robin
+ * @date 2022/1/29 15:35
+ */
+public class LeetCode16 {
+
+    private static final Integer[] ARRAY = {3, 1, 5, 7, 9, 11};
+
+
+    public static void main(String[] args) {
+        // 生成别墅
+//        Integer[] array = new Integer[10];
+        // 给每个别墅随机加钱
+//        for (int i = 0; i < array.length; i++) {
+//            array[i] = ThreadLocalRandom.current().nextInt(0, 100);
+//        }
+        // 打印出别墅的排列
+        System.out.println(Arrays.toString(ARRAY));
+        // 小偷开始偷钱
+        Integer robberies = robberies(ARRAY);
+        // 小偷一共偷了多少钱
+        System.out.println(robberies);
+    }
+
+    /**
+     * @param array 数组
+     * @return 总金额
+     */
+    private static Integer robberies(Integer[] array) {
+        // 小偷偷的钱的总额
+        int count = 0;
+        for (int i = 0; i < array.length; i += 2) {
+            int max = Math.max(array[i], i < array.length - 1 ? array[i + 1] : array[i]);
+            System.out.printf("%d + %d = %d%n", count, max, count + max);
+            count += max;
+
+        }
+
+        return count;
+    }
+
+
+    /**
+     * 深度优化
+     *
+     * @param array 数组
+     * @return 总金额
+     */
+//    private static Integer robberies(Integer[] array) {
+//        int a = 0;
+//        int b = 0;
+//
+//        for (Integer integer : array) {
+//            int temp = b;
+//            b = Math.max(a + integer, b);
+//            System.out.printf("%d + %d = %d%n", a, integer, a + integer);
+//            a = temp;
+//        }
+//
+//        return b;
+//    }
+}

datastructure/src/main/java/org/alis/smallcc/algorithm/redpackage/DoubleDivide.java

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+package org.alis.smallcc.algorithm.redpackage;
+
+import java.util.Random;
+import java.util.concurrent.ThreadLocalRandom;
+
+/**
+ * 红包算法只
+ * 双倍平均算法
+ * <p>
+ * 红包的最小单位是分 所以这里需要执行乘100的倍数
+ *
+ * @author robin
+ * @date 2022/2/7 10:22
+ */
+public class DoubleDivide {
+
+    public static void main(String[] args) {
+        dividePackage(10000, 10);
+    }
+
+
+    /**
+     * 双倍算法
+     *
+     * @param total 总金额
+     * @param count 总份数
+     */
+    private static void dividePackage(Integer total, Integer count) {
+        int temp = count;
+        int endCount = 0;
+        int min = 1;
+        for (int i = 1; i <= temp; i++) {
+            int amount;
+            if (i == temp) {
+                amount = total;
+            } else {
+                amount = Math.max(min, ThreadLocalRandom.current().nextInt(total / count * 2 - 1) + 1 - min);
+            }
+            total -= amount;
+            count--;
+            System.out.printf("第%d 个人抢到了 %f 元%n", i, (float) amount / 100);
+            endCount += amount;
+        }
+        System.out.printf("红包的总数是%d %n", endCount);
+    }
+
+
+}

datastructure/src/main/java/org/alis/smallcc/algorithm/redpackage/RandomRedPackage.java

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+package org.alis.smallcc.algorithm.redpackage;
+
+import java.util.concurrent.ThreadLocalRandom;
+
+/**
+ * 随机红包
+ * 前几名拿高额钱包一定是最大的
+ *
+ * @author robin
+ * @date 2022/2/7 10:54
+ */
+public class RandomRedPackage {
+    public static void main(String[] args) {
+        random(10000, 10);
+    }
+
+    private static void random(Integer total, Integer count) {
+        int min = 1;
+        for (int i = 1; i <= count; i++) {
+            int amount;
+            if (i == count) {
+                amount = total;
+            } else {
+                amount = Math.max(min, ThreadLocalRandom.current().nextInt(total - 1) + 1 - min);
+            }
+            total -= amount;
+            System.out.printf("第%d 个人抢到了 %f 元%n", i, (float) amount / 100);
+        }
+    }
+
+}

datastructure/src/main/java/org/alis/smallcc/algorithm/redpackage/SegmentRedPackage.java

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+package org.alis.smallcc.algorithm.redpackage;
+
+import java.util.*;
+import java.util.stream.Collectors;
+
+/**
+ * 分段
+ * 线段切割算法
+ *
+ * @author robin
+ * @date 2022/2/7 11:32
+ */
+public class SegmentRedPackage {
+
+    public static void main(String[] args) {
+        List<Integer> integers = lineCut(10000, 10);
+    }
+
+    private static List<Integer> lineCut(int money, int people) {
+
+        if (money < 1 || people < 1 || money < people) {
+            return Collections.emptyList();
+        }
+
+        List<Integer> team = new ArrayList<>(people - 1);
+        List<Integer> result = new ArrayList<>(people);
+
+        Random random = new Random();
+        while (team.size() < people - 1) {
+            int randomMoney = random.nextInt(money) + 1;
+            if (!team.contains(randomMoney)) {
+                team.add(randomMoney);
+            }
+        }
+
+        Collections.sort(team);
+
+        System.out.print("分割点：");
+        System.out.println(team.stream().map(Integer::floatValue).map(f->f/100).collect(Collectors.toList()));
+
+        int left = 0;
+        for (Integer integer : team) {
+            result.add(integer - left);
+            left = integer;
+        }
+        result.add(money - left);
+
+        System.out.print("每人金额：");
+        System.out.println(result.stream().map(Integer::floatValue).map(f->f/100).collect(Collectors.toList()));
+
+        // 验证分割后的数是否是输入的总金额
+        result.stream().reduce(Integer::sum).ifPresent(amount -> {
+            System.out.print("总金额：");
+            System.out.println(amount);
+        });
+
+        return result;
+    }
+
+
+}