添加了五个LeetCode问题的解决方案，优化了代码结构。

LeetCode15_$

src/main/java/cn/whaifree/redo/redo_all_240511/LeetCode142.java

@@ -0,0 +1,43 @@
+package cn.whaifree.redo.redo_all_240511;
+
+import cn.whaifree.leetCode.model.ListNode;
+import org.junit.Test;
+
+/**
+ * @version 1.0
+ * @Author whai文海
+ * @Date 2024/6/2 14:49
+ * @注释
+ */
+public class LeetCode142 {
+
+    @Test
+    public void test() {
+        ListNode node = ListNode.listNodeFromArray(new int[]{1,3,2});
+        node.next.next.next = node.next;
+        System.out.println(new Solution().detectCycle(node).val);
+    }
+
+
+    public class Solution {
+        public ListNode detectCycle(ListNode head) {
+            ListNode fast = head;
+            ListNode slow = head;
+            do {
+                if (fast == null || fast.next == null) {
+                    return null;
+                }
+                fast = fast.next.next;
+                slow = slow.next;
+            } while (fast != slow);
+
+
+            fast = head;
+            while (fast != slow) {
+                fast = fast.next;
+                slow = slow.next;
+            }
+            return fast;
+        }
+    }
+}

src/main/java/cn/whaifree/redo/redo_all_240511/LeetCode15_$.java

@@ -0,0 +1,60 @@
+package cn.whaifree.redo.redo_all_240511;
+
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * FIXME： 24-6-2
+ *
+ * @version 1.0
+ * @Author whai文海
+ * @Date 2024/6/2 20:43
+ * @注释
+ */
+public class LeetCode15_$ {
+
+    @Test
+    public void test() {
+        int[] nums = {-1, 0, 1, 2, -1, -4};
+        Solution solution = new Solution();
+        List<List<Integer>> lists = solution.threeSum(nums);
+        System.out.println(lists);
+    }
+
+    class Solution {
+        public List<List<Integer>> threeSum(int[] nums) {
+            List<List<Integer>> result = new ArrayList<>();
+            Arrays.sort(nums);
+
+            for (int i = 0; i < nums.length - 2; i++) {
+                if (i > 0 && nums[i] == nums[i - 1]) {
+                    continue;
+                }
+                int left = i + 1;
+                int right = nums.length - 1;
+                while (left < right) {
+                    int sum = nums[i] + nums[left] + nums[right];
+                    if (sum == 0) {
+                        result.add(Arrays.asList(nums[i], nums[left], nums[right]));
+                        while (left < right && nums[left] == nums[left + 1]) {
+                            left++;
+                        }
+                        while (left < right && nums[right] == nums[right - 1]) {
+                            right--;
+                        }
+                        left++;
+                        right--;
+                    } else if (sum < 0) {
+                        left++;
+                    } else {
+                        right--;
+                    }
+                }
+            }
+            return result;
+        }
+    }
+}

src/main/java/cn/whaifree/redo/redo_all_240511/LeetCode202.java

@@ -0,0 +1,52 @@
+package cn.whaifree.redo.redo_all_240511;
+
+import org.junit.Test;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * @version 1.0
+ * @Author whai文海
+ * @Date 2024/6/2 16:25
+ * @注释
+ */
+public class LeetCode202 {
+
+    @Test
+    public void test() {
+        Solution solution = new Solution();
+        boolean happy = solution.isHappy(19);
+        System.out.println(happy);
+    }
+
+    class Solution {
+        /**
+         * 2 4 16 37 56 61  37 出现循环
+         * @param n
+         * @return
+         */
+        public boolean isHappy(int n) {
+            int tmp = n;
+            Set<Integer> set = new HashSet<>();
+            while (tmp != 1) {
+                set.add(tmp);
+                tmp = get(tmp);
+                if (set.contains(tmp)) {
+                    return false;
+                }
+            }
+            return true;
+        }
+
+        public int get(int num) {
+            int sum = 0;
+            while (num != 0) {
+                int retail = num % 10;
+                num /= 10;
+                sum += retail * retail;
+            }
+            return sum;
+        }
+    }
+}

src/main/java/cn/whaifree/redo/redo_all_240511/LeetCode2487.java

@@ -0,0 +1,54 @@
+package cn.whaifree.redo.redo_all_240511;
+
+import cn.whaifree.leetCode.model.ListNode;
+import org.junit.Test;
+
+/**
+ * @version 1.0
+ * @Author whai文海
+ * @Date 2024/6/2 16:34
+ * @注释
+ */
+public class LeetCode2487 {
+    @Test
+    public void test() {
+        ListNode listNode = ListNode.listNodeFromArray(new int[]{1, 1, 1, 1});
+        new Solution().removeNodes(listNode).printList();
+    }
+
+    class Solution {
+        public ListNode removeNodes(ListNode head) {
+            head = reverse(head);
+            // 如果左侧会更大，前移动
+            // 如果左侧会更小，删除左侧
+            ListNode tmp = head;
+            ListNode pre = head;
+            while (tmp!= null) {
+                // 找到比pre小的
+                if (tmp.val < pre.val) {
+                    pre.next = tmp.next;
+                }else {
+                    pre = tmp;
+                }
+                tmp = tmp.next;
+            }
+
+
+            return reverse(head);
+        }
+
+        public ListNode reverse(ListNode head) {
+            return reverseList(null, head);
+        }
+
+        public ListNode reverseList(ListNode pre, ListNode after) {
+            if (after == null) {
+                return pre;
+            }
+            ListNode tmp = after.next;
+            after.next = pre;
+            return reverseList(after, tmp);
+        }
+    }
+
+}

src/main/java/cn/whaifree/redo/redo_all_240511/LeetCode287.java

@@ -0,0 +1,64 @@
+package cn.whaifree.redo.redo_all_240511;
+
+import org.junit.Test;
+
+/**
+ * @version 1.0
+ * @Author whai文海
+ * @Date 2024/6/2 14:37
+ * @注释
+ */
+public class LeetCode287 {
+
+    @Test
+    public void test() {
+        int[] nums = {3, 1, 3, 4, 2};
+        Solution solution = new Solution();
+        int i = solution.findDuplicate(nums);
+        System.out.println(i);
+    }
+
+    class Solution {
+        /**
+         * 成环路
+         *
+         * 1 3 4 2 2
+         * 0 1 2 3 4
+         *
+         * 0--->1--->3--->2--->4--->2
+         *
+         * 3 1 3 4 2
+         * 0 1 2 3 4
+         *
+         * 0->3-->4-->2
+         *
+         * 快慢指针
+         *，类似链表操作
+         * i=0
+         * next i=nums[i]
+         * nexr.next i=nums[nums[i]]
+         *
+         * @param nums
+         * @return
+         */
+        public int findDuplicate(int[] nums) {
+            int fast = 0;
+            int slow = 0;
+            do {
+                fast = nums[nums[fast]];
+                slow = nums[slow];
+            } while (fast != slow);
+
+            // 找到相交点
+            fast = 0;
+            while (fast != slow) {
+                fast = nums[fast];
+                slow = nums[slow];
+            }
+
+            return fast;
+        }
+    }
+
+
+}