leecode更新

Leecode/src/main/java/com/markilue/leecode/hot100/second/T04_4_FindMedianSortedArrays.java

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+package com.markilue.leecode.hot100.second;
+
+import org.junit.Test;
+
+/**
+ *@BelongsProject: Leecode
+ *@BelongsPackage: com.markilue.leecode.hot100.second
+ *@Author: markilue
+ *@CreateTime: 2023-04-20  11:28
+ *@Description:
+ * TODO  力扣4题  寻找两个正序数组的中位数:
+ *   给定两个大小分别为 m 和 n 的正序（从小到大）数组 nums1 和 nums2。请你找出并返回这两个正序数组的 中位数 。
+ *   算法的时间复杂度应该为 O(log (m+n)) 。
+ *@Version: 1.0
+ */
+public class T04_4_FindMedianSortedArrays {
+
+    @Test
+    public void test(){
+        int[] nums1={1,3};
+        int[] nums2={2};
+        System.out.println(findMedianSortedArrays(nums1,nums2));
+    }
+
+    public double findMedianSortedArrays(int[] nums1, int[] nums2) {
+        int n = nums1.length;
+        int m = nums2.length;
+        int left = (n + m + 1) / 2;
+        int right = (n + m + 2) / 2;
+        ////将偶数和奇数的情况合并，如果是奇数，会求两次同样的 k 。
+        //比如n=5,m=5,则left=5,right=6;  合理
+        //比如n=5,m=6,则left=6,right=6;  合理
+        return (getKth(nums1, 0, n - 1, nums2, 0, m - 1, left) + getKth(nums1, 0, n - 1, nums2, 0, m - 1, right)) * 0.5;
+
+
+    }
+
+    private int getKth(int[] nums1, int start1, int end1, int[] nums2, int start2, int end2, int k) {
+        int len1 = end1 - start1 + 1;
+        int len2 = end2 - start2 + 1;
+        //保证如果数组空了，就一定是len1
+        if (len1 > len2) return getKth(nums2, start2, end2, nums1, start1, end1, k);
+        if (len1 == 0) return nums2[start2 + k - 1];
+
+        if (k == 1) return Math.min(nums1[start1], nums2[start2]);
+        //会直接比较k/2的位置
+        int i = start1 + Math.min(len1, k / 2) - 1;
+        int j = start2 + Math.min(len2, k / 2) - 1;
+
+        if (nums1[i] > nums2[j]) {
+            return getKth(nums1, start1, end1, nums2, j + 1, end2, k - (j - start2 + 1));//j-start2+1就抛弃的长度
+        } else {
+            return getKth(nums1, i + 1, end1, nums2, start2, end2, k - (i - start1 + 1));//i - start1 + 1就是抛弃的长度
+        }
+
+    }
+}

Leecode/src/main/java/com/markilue/leecode/hot100/second/T10_10_IsMatch.java

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+package com.markilue.leecode.hot100.second;
+
+/**
+ *@BelongsProject: Leecode
+ *@BelongsPackage: com.markilue.leecode.hot100.second
+ *@Author: markilue
+ *@CreateTime: 2023-04-20  11:57
+ *@Description:
+ * TODO  力扣10  正则表达式匹配:
+ *  给你一个字符串 s 和一个字符规律 p，请你来实现一个支持 '.' 和 '*' 的正则表达式匹配。
+ *   '.' 匹配任意单个字符
+ *   '*' 匹配零个或多个前面的那一个元素
+ *   所谓匹配，是要涵盖 整个 字符串 s的，而不是部分字符串。
+ *@Version: 1.0
+ */
+public class T10_10_IsMatch {
+
+    /**
+     * 动态规划法:dp[i][j]表示使用s[0-i]和p[0-j]能否匹配上
+     * @param s
+     * @param p
+     * @return
+     */
+    public boolean isMatch(String s, String p) {
+        int m = s.length();
+        int n = p.length();
+
+        boolean[][] dp = new boolean[m + 1][n + 1];
+        dp[0][0] = true;
+
+        for (int i = 0; i < dp.length; i++) {
+            for (int j = 1; j < dp[0].length; j++) {
+                if (p.charAt(j - 1) == '*') {
+                    dp[i][j] = dp[i][j - 2];//不匹配字符，将该组合扔掉，不再进行匹配。
+                    if (matches(s, p, i, j - 1)) {
+                        //如果当前值还和上一个一样
+                        dp[i][j] |= dp[i - 1][j];////能匹配 s 末尾的一个字符，将该字符扔掉，而该组合还可以继续进行匹配；
+                    }
+                } else {
+                    if (matches(s, p, i, j)) {
+                        dp[i][j] = dp[i - 1][j - 1];
+                    }
+                }
+            }
+        }
+        return dp[m][n];
+
+    }
+
+    public boolean matches(String s, String p, int i, int j) {
+        if (i == 0) return false;
+        if (p.charAt(j - 1) == '.') {
+            return true;
+        }
+
+        return s.charAt(i - 1) == p.charAt(j - 1);
+
+    }
+}

Leecode/src/main/java/com/markilue/leecode/hot100/second/T11_15_ThreeSum.java

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+package com.markilue.leecode.hot100.second;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ *@BelongsProject: Leecode
+ *@BelongsPackage: com.markilue.leecode.hot100.second
+ *@Author: markilue
+ *@CreateTime: 2023-04-22  11:10
+ *@Description:
+ * TODO  力扣15  三数之和:
+ *   给你一个整数数组 nums ，判断是否存在三元组 [nums[i], nums[j], nums[k]] 满足 i != j、i != k 且 j != k ，同时还满足 nums[i] + nums[j] + nums[k] == 0 。请
+ *   你返回所有和为 0 且不重复的三元组。
+ *   注意：答案中不可以包含重复的三元组。
+ *@Version: 1.0
+ */
+public class T11_15_ThreeSum {
+
+    public List<List<Integer>> threeSum(int[] nums) {
+
+        Arrays.sort(nums);
+
+        List<List<Integer>> result = new ArrayList<>();
+
+        for (int i = 0; i < nums.length; i++) {
+            if (nums[i] > 0) break;
+            if (i != 0 && nums[i] == nums[i - 1]) {
+                continue;
+            }
+
+            int left = i + 1;
+            int right = nums.length - 1;
+
+            while (left < right) {
+                long sum = nums[left] + nums[right];
+                if (-nums[i] < sum) {
+                    //>0
+                    right--;
+                } else if (-nums[i] > sum) {
+                    left++;
+                } else {
+                    //刚好符合
+                    result.add(new ArrayList<>(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--;
+                }
+            }
+        }
+
+        return result;
+    }
+}

Leecode/src/main/java/com/markilue/leecode/hot100/second/T12_17_LetterCombinations.java

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+package com.markilue.leecode.hot100.second;
+
+import org.omg.CORBA.PUBLIC_MEMBER;
+
+import java.sql.Array;
+import java.util.*;
+
+/**
+ *@BelongsProject: Leecode
+ *@BelongsPackage: com.markilue.leecode.hot100.second
+ *@Author: markilue
+ *@CreateTime: 2023-04-22  11:32
+ *@Description:
+ * TODO  力扣17  电话号码的字母组合:
+ *   给定一个仅包含数字 2-9 的字符串，返回所有它能表示的字母组合。答案可以按 任意顺序 返回。
+ *   给出数字到字母的映射如下（与电话按键相同）。注意 1 不对应任何字母。
+ *@Version: 1.0
+ */
+public class T12_17_LetterCombinations {
+
+    Map<Character, List<Character>> map = new HashMap() {{
+        put('2', Arrays.asList('a', 'b', 'c'));
+        put('3', Arrays.asList('d', 'e', 'f'));
+        put('4', Arrays.asList('g', 'h', 'i'));
+        put('5', Arrays.asList('j', 'k', 'l'));
+        put('6', Arrays.asList('m', 'n', 'o'));
+        put('7', Arrays.asList('p', 'q', 'r', 's'));
+        put('8', Arrays.asList('t', 'u', 'v'));
+        put('9', Arrays.asList('w', 'x', 'y', 'z'));
+    }};
+
+
+    List<String> result = new ArrayList<>();
+    StringBuilder sb = new StringBuilder();
+
+    public List<String> letterCombinations(String digits) {
+        if (digits.length() == 0) return result;
+        backtracking(digits.toCharArray(), 0);
+        return result;
+    }
+
+    public void backtracking(char[] chars, int startIndex) {
+        if (startIndex == chars.length) {
+            result.add(sb.toString());
+            return;
+        }
+
+        List<Character> list = map.get(chars[startIndex]);
+
+        for (Character character : list) {
+            sb.append(character);
+            backtracking(chars, startIndex + 1);
+            sb.deleteCharAt(sb.length() - 1);
+        }
+
+    }
+}

Leecode/src/main/java/com/markilue/leecode/hot100/second/T13_19_RemoveNthFromEnd.java

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+package com.markilue.leecode.hot100.second;
+
+import com.markilue.leecode.listnode.ListNode;
+
+/**
+ *@BelongsProject: Leecode
+ *@BelongsPackage: com.markilue.leecode.hot100.second
+ *@Author: markilue
+ *@CreateTime: 2023-04-22  11:42
+ *@Description:
+ * TODO  力扣19  删除链表的倒数第N个节点:
+ *   给你一个链表，删除链表的倒数第 n 个结点，并且返回链表的头结点。
+ *@Version: 1.0
+ */
+public class T13_19_RemoveNthFromEnd {
+
+    public ListNode removeNthFromEnd(ListNode head, int n) {
+
+        ListNode fake = new ListNode();
+        fake.next = head;
+        ListNode fast = fake;
+        ListNode slow = fake;
+
+        while (fast != null && n-- > 0) {
+            fast = fast.next;
+        }
+        if (fast == null) {
+            //不够
+            return head;
+        }
+        while (fast.next != null) {
+            //走到头
+            fast = fast.next;
+            slow = slow.next;
+        }
+        slow.next = slow.next.next;
+        return fake.next;
+
+
+    }
+}

Leecode/src/main/java/com/markilue/leecode/hot100/second/T14_20_IsValid.java

@@ -0,0 +1,44 @@
+package com.markilue.leecode.hot100.second;
+
+import java.util.ArrayDeque;
+import java.util.Deque;
+import java.util.HashMap;
+
+/**
+ *@BelongsProject: Leecode
+ *@BelongsPackage: com.markilue.leecode.hot100.second
+ *@Author: markilue
+ *@CreateTime: 2023-04-22  11:50
+ *@Description:
+ * TODO  力扣20  有效的括号:
+ *   给定一个只包括 '('，')'，'{'，'}'，'['，']' 的字符串 s ，判断字符串是否有效。
+ *   有效字符串需满足：
+ *   左括号必须用相同类型的右括号闭合。
+ *   左括号必须以正确的顺序闭合。
+ *   每个右括号都有一个对应的相同类型的左括号。
+ *@Version: 1.0
+ */
+public class T14_20_IsValid {
+
+    public boolean isValid(String s) {
+        HashMap<Character, Character> map = new HashMap() {{
+            put('(', ')');
+            put('[', ']');
+            put('{', '}');
+        }};
+
+        Deque<Character> stack = new ArrayDeque<>();
+
+        for (char c : s.toCharArray()) {
+            if (map.containsKey(c)) {
+                stack.push(map.get(c));
+            } else {
+                if (stack.isEmpty() || c != stack.peek()) return false;
+                stack.pop();
+            }
+        }
+
+        return stack.size()==0;
+
+    }
+}

Leecode/src/main/java/com/markilue/leecode/hot100/second/T15_21_MergeTwoLists.java

@@ -0,0 +1,41 @@
+package com.markilue.leecode.hot100.second;
+
+import com.markilue.leecode.listnode.ListNode;
+
+/**
+ *@BelongsProject: Leecode
+ *@BelongsPackage: com.markilue.leecode.hot100.second
+ *@Author: markilue
+ *@CreateTime: 2023-04-22  11:59
+ *@Description:
+ * TODO  力扣21  合并两个有序链表:
+ *   将两个升序链表合并为一个新的 升序 链表并返回。新链表是通过拼接给定的两个链表的所有节点组成的。
+ *@Version: 1.0
+ */
+public class T15_21_MergeTwoLists {
+
+    /**
+     *
+     * @param list1
+     * @param list2
+     * @return
+     */
+    public ListNode mergeTwoLists(ListNode list1, ListNode list2) {
+        if (list1 == null) {
+            return list2;
+        } else if (list2 == null) {
+            return list1;
+        }
+        ListNode root = new ListNode();
+        if (list1.val < list2.val) {
+            root.val = list1.val;
+            root.next = mergeTwoLists(list1.next, list2);
+        } else {
+            root.val = list2.val;
+            root.next = mergeTwoLists(list1, list2.next);
+        }
+
+        return root;
+
+    }
+}

Leecode/src/main/java/com/markilue/leecode/hot100/second/T16_22_GenerateParenthesis.java

@@ -0,0 +1,55 @@
+package com.markilue.leecode.hot100.second;
+
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ *@BelongsProject: Leecode
+ *@BelongsPackage: com.markilue.leecode.hot100.second
+ *@Author: markilue
+ *@CreateTime: 2023-04-22  12:09
+ *@Description:
+ * TODO  力扣22  括号生成:
+ *   数字 n 代表生成括号的对数，请你设计一个函数，用于能够生成所有可能的并且 有效的 括号组合。
+ *@Version: 1.0
+ */
+public class T16_22_GenerateParenthesis {
+
+    @Test
+    public void test() {
+        System.out.println(generateParenthesis(3));
+    }
+
+    List<String> result = new ArrayList<>();
+    StringBuilder sb = new StringBuilder();
+
+
+    public List<String> generateParenthesis(int n) {
+        backtracking(n, 0, 0);
+        return result;
+    }
+
+    public void backtracking(int n, int left, int right) {
+        if (left > n || right > n || right > left) return;
+        if (left == n && right == n) {
+            result.add(sb.toString());
+            return;
+        }
+
+        if (left < n) {
+            sb.append('(');
+            backtracking(n, left + 1, right);
+            sb.deleteCharAt(sb.length() - 1);
+        }
+
+        if (right < n) {
+            sb.append(')');
+            backtracking(n, left, right + 1);
+            sb.deleteCharAt(sb.length() - 1);
+        }
+
+    }
+
+}

Leecode/src/main/java/com/markilue/leecode/interview/meituan/LC_25_ReverseKGroup.java

@@ -0,0 +1,69 @@
+package com.markilue.leecode.interview.meituan;
+
+import com.markilue.leecode.listnode.ListNode;
+import com.markilue.leecode.listnode.ListNodeUtils;
+import org.junit.Test;
+
+/**
+ *@BelongsProject: Leecode
+ *@BelongsPackage: com.markilue.leecode.interview.meituan
+ *@Author: markilue
+ *@CreateTime: 2023-04-21  11:12
+ *@Description:
+ * TODO  力扣25  K 个一组翻转链表:
+ *   给你链表的头节点 head ，每 k 个节点一组进行翻转，请你返回修改后的链表。
+ *   k 是一个正整数，它的值小于或等于链表的长度。如果节点总数不是 k 的整数倍，那么请将最后剩余的节点保持原有顺序。
+ *   你不能只是单纯的改变节点内部的值，而是需要实际进行节点交换。
+ *@Version: 1.0
+ */
+public class LC_25_ReverseKGroup {
+
+
+    @Test
+    public void test(){
+        ListNode root = ListNodeUtils.build(new int[]{1, 2, 3, 4, 5});
+        ListNodeUtils.print(reverseKGroup(root,2));
+    }
+
+    public ListNode reverseKGroup(ListNode head, int k) {
+
+        if (head == null) {
+            return head;
+        }
+        ListNode temp = head;
+        for (int i = 0; i < k; i++) {
+            if (temp == null) return head;//不足k个
+            temp = temp.next;
+        }
+
+        ListNode newHead = reverse(head, temp);
+        head.next = reverseKGroup(temp, k);
+
+        return newHead;
+
+    }
+
+    /**
+     * 反转从head到end
+     * @param head
+     * @param end
+     * @return
+     */
+    public ListNode reverse(ListNode head, ListNode end) {
+        if(head==null) return head;
+
+        ListNode fake = new ListNode();
+        ListNode temp = head;
+
+        ListNode temp1;
+
+        while (temp != end) {
+            temp1 = temp.next;
+            temp.next = fake.next;
+            fake.next = temp;
+            temp = temp1;
+        }
+
+        return fake.next;
+    }
+}

Leecode/src/main/java/com/markilue/leecode/interview/meituan/LC_45_Jump.java

@@ -0,0 +1,64 @@
+package com.markilue.leecode.interview.meituan;
+
+import org.junit.Test;
+
+/**
+ *@BelongsProject: Leecode
+ *@BelongsPackage: com.markilue.leecode.interview.meituan
+ *@Author: markilue
+ *@CreateTime: 2023-04-21  11:41
+ *@Description: TODO  力扣45  跳跃游戏II:
+ *@Version: 1.0
+ */
+public class LC_45_Jump {
+
+    @Test
+    public void test(){
+        int[] nums={2,3,1,1,4};
+        System.out.println(jump1(nums));
+    }
+
+    public int jump(int[] nums) {
+        if (nums.length == 1) {
+            return 0;
+        }
+
+        int maxGet = nums[0];
+        int lastGet = nums[0];
+        int cur = 1;
+        for (int i = 1; i < nums.length - 1; i++) {
+            if (lastGet < i) {
+                cur++;
+                lastGet = maxGet;
+            }
+            maxGet = Math.max(maxGet, nums[i] + i);
+            if (maxGet >= nums.length - 1) return cur + 1;
+        }
+
+
+        return maxGet > nums.length - 1 ? cur : 0;
+
+    }
+
+    public int jump1(int[] nums) {
+        if (nums.length == 1) {
+            return 0;
+        }
+
+        int maxGet = -1;
+        int lastGet = -1;
+        int cur = 0;
+        for (int i = 0; i < nums.length - 1; i++) {
+            if (lastGet < i) {
+                cur++;
+                lastGet = maxGet;
+            }
+            maxGet = Math.max(maxGet, nums[i] + i);
+            if (maxGet >= nums.length - 1) return cur ;
+        }
+
+
+        return maxGet >= nums.length - 1 ? cur : 0;
+
+    }
+}

Leecode/src/main/java/com/markilue/leecode/interview/meituan/LC_71_SimplifyPath.java

@@ -0,0 +1,164 @@
+package com.markilue.leecode.interview.meituan;
+
+import org.junit.Test;
+
+import java.io.IOException;
+import java.io.StreamTokenizer;
+import java.util.ArrayDeque;
+import java.util.Deque;
+
+/**
+ *@BelongsProject: Leecode
+ *@BelongsPackage: com.markilue.leecode.interview.meituan
+ *@Author: markilue
+ *@CreateTime: 2023-04-21  10:15
+ *@Description: TODO  力扣71  简化路径
+ *@Version: 1.0
+ */
+public class LC_71_SimplifyPath {
+
+    public static void main(String[] args) throws IOException {
+//        StreamTokenizer re = new StreamTokenizer(System.in);
+//        re.nextToken();
+//        int int1 = (int)re.nval;
+//        System.out.println(int1);
+        for (int i = 0; i < 5; i++) {
+            new Thread(new Runnable(){
+                public void run(){
+                    System.out.println(Thread.currentThread().getName());
+                }
+            },"thread"+i).start();
+        }
+
+
+    }
+
+    @Test
+    public void test() {
+        String path = "/a/./b/../../c/";
+        System.out.println(simplifyPath1(path));
+    }
+
+    @Test
+    public void test1() {
+        String path = "/home//foo/";
+        System.out.println(simplifyPath2(path));
+    }
+
+    @Test
+    public void test2() {
+        String path = "/.";
+        System.out.println(simplifyPath(path));
+    }
+
+    @Test
+    public void test3() {
+        String path = "/abc";
+        System.out.println(simplifyPath(path));
+    }
+
+    public String simplifyPath(String path) {
+
+        StringBuilder sb = new StringBuilder();
+        char[] chars = path.toCharArray();
+        if (chars[0] == '/') {
+            sb.append('/');
+        }
+
+        for (int i = 1; i < chars.length; i++) {
+            if (Character.isLetterOrDigit(chars[i])) {
+                while (i < chars.length && (Character.isLetterOrDigit(chars[i]) || chars[i] == '_')) {
+                    sb.append(chars[i]);
+                    i++;
+                }
+                i--;//不是之后回退一步
+            } else if (chars[i] == '.') {
+
+                if (i + 1 < chars.length && chars[i + 1] == '.') {
+                    for (int j = 0; j < 2; j++) {
+                        if (sb.length() == 0) {
+                            continue;
+                        }
+                        int index = sb.lastIndexOf("/");
+                        sb.delete(index, sb.length());
+                    }
+                    i++;
+                }
+            } else if (chars[i] == '/') {
+                if (sb.length() == 0 || sb.charAt(sb.length() - 1) != '/') {
+                    sb.append(chars[i]);
+                }
+            }
+        }
+        if (sb.length() == 0) {
+            sb.append('/');
+        }
+        if (sb.length() > 1 && sb.charAt(sb.length() - 1) == '/') {
+            sb.deleteCharAt(sb.length() - 1);
+        }
+
+        return sb.toString();
+
+    }
+
+
+    /**
+     * 官方题解:使用一个栈记录
+     * 速度击败49.47%   内存击败43.46%  4ms
+     * @param path
+     * @return
+     */
+    public String simplifyPath1(String path) {
+        String[] name = path.split("/");
+        Deque<String> stack = new ArrayDeque<>();
+
+        for (String s : name) {
+            if ("..".equals(s)) {
+                if (!stack.isEmpty()) {
+                    stack.pollLast();
+                }
+            } else if (s.length() > 0 && !".".equals(s)) {
+                stack.offerLast(s);
+            }
+        }
+
+        StringBuilder sb = new StringBuilder();
+        if (stack.isEmpty()) {
+            sb.append("/");
+        } else {
+            while (!stack.isEmpty()) {
+                sb.append("/");
+                sb.append(stack.pollFirst());
+            }
+        }
+
+        return sb.toString();
+
+    }
+
+    //优秀解法:不用split,挨个找，也可以直接避免split之后有的为""的情况;速度击败98.98%  内存击败21.42%
+    public String simplifyPath2(String path) {
+        Deque<String> deque = new ArrayDeque<>();
+        int n = path.length();
+        for (int i = 1; i < n; i++) {
+            if (path.charAt(i) == '/') continue;   // 找到下一个不是"/"的位置
+            int j = i + 1;   // j指向下一个位置，双指针！
+            while (j < n && path.charAt(j) != '/') j++; // 直到j指向的位置是"/"
+            String temp = path.substring(i, j);   // 左闭右开，[i.j)
+            if (temp.equals("..")) {     //..的时候，栈内有元素才删
+                if (!deque.isEmpty()) {
+                    deque.pollLast();
+                }
+            } else if (!(temp.equals("."))) { // .的时候就continue，这里省略了，不是.的时候就进栈
+                deque.addLast(temp);
+            }
+            i = j; //j是指向"/"的，令i=j开始下一轮循环
+        }
+        StringBuilder ans = new StringBuilder();
+        while (!deque.isEmpty()) {  // 还原栈内的路径
+            ans.append("/");
+            ans.append(deque.pollFirst());
+        }
+        return ans.length() == 0 ? "/" : ans.toString();  // 栈为空就直接返回"/",否则返回ans.toString()
+    }
+}

Leecode/src/main/java/com/markilue/leecode/listnode/selftry/ReorderList.java

@@ -1,6 +1,8 @@
 package com.markilue.leecode.listnode.selftry;
 
 import com.markilue.leecode.listnode.ListNode;
+import com.markilue.leecode.listnode.ListNodeUtils;
+import org.junit.Test;
 
 /**
  *@BelongsProject: Leecode
@@ -18,6 +20,13 @@ import com.markilue.leecode.listnode.ListNode;
  */
 public class ReorderList {
 
+    @Test
+    public void test() {
+        ListNode root = ListNodeUtils.build(new int[]{1, 2, 3, 4, 5});
+        reorderList(root);
+        ListNodeUtils.print(root);
+    }
+
 
     /**
      * 递归法

Leecode/src/main/java/com/markilue/leecode/listnode/selftry/ReorderListII.java

@@ -0,0 +1,38 @@
+package com.markilue.leecode.listnode.selftry;
+
+import com.markilue.leecode.listnode.ListNode;
+
+/**
+ *@BelongsProject: Leecode
+ *@BelongsPackage: com.markilue.leecode.listnode.selftry
+ *@Author: markilue
+ *@CreateTime: 2023-04-21  10:06
+ *@Description: TODO
+ *@Version: 1.0
+ */
+public class ReorderListII {
+
+
+    ListNode p;
+
+    public void reorderList(ListNode head) {
+        p = head;
+        recur(head);
+    }
+
+    public void recur(ListNode head) {
+        if (head == null) {
+            return;
+        }
+        recur(head.next);
+
+        if (p.next == null || head == p || head.next == p) {
+            //已经运行到了
+            p.next = null;
+            return;
+        }
+        head.next = p.next;
+        p.next = head;
+        p = p.next.next;
+    }
+}

interview/Huawei/src/main/java/com/markilue/interview/Question1.java

@@ -32,23 +32,23 @@ public class Question1 {
                 return o1[0] == o2[0] ? o1[1] - o2[1] : o1[0] - o2[0];
             }
         });
-        int res=0;
+        int res = 0;
         ArrayList<int[]> single = new ArrayList<>();
         ArrayList<int[]> multi = new ArrayList<>();
         for (int i = 0; i < nums.length; i++) {
-            if(nums[i][0]<=nums[i-1][1]){
+            if (nums[i][0] <= nums[i - 1][1]) {
-                if(multi.size()>0&&nums[i][0]<multi.get(multi.size()-1)[1]){
+                if (multi.size() > 0 && nums[i][0] < multi.get(multi.size() - 1)[1]) {
-                    nums[i][0] = multi.get(multi.size()-1)[1];
+                    nums[i][0] = multi.get(multi.size() - 1)[1];
-                    if(nums[i][1]<nums[i-1][1]){
+                    if (nums[i][1] < nums[i - 1][1]) {
                         int[] temp = nums[i];
-                        nums[i]=nums[i-1];
+                        nums[i] = nums[i - 1];
-                        nums[i-1]=temp;
+                        nums[i - 1] = temp;
                     }
                 }
-                if(nums[i-1][0]!=nums[i][0])single.add(new int[]{nums[i-1][0],nums[i][0]});
+                if (nums[i - 1][0] != nums[i][0]) single.add(new int[]{nums[i - 1][0], nums[i][0]});
-                if(nums[i][0]!=nums[i-1][1])multi.add(new int[]{nums[i][0],nums[i-1][1]});
+                if (nums[i][0] != nums[i - 1][1]) multi.add(new int[]{nums[i][0], nums[i - 1][1]});
-            }else {
+            } else {
-                single.add(nums[i-1]);
+                single.add(nums[i - 1]);
             }
         }
 
@@ -71,7 +71,7 @@ public class Question1 {
     public void test() {
         int[][] nums = new int[][]{{2, 5}, {8, 9}};
 //        int[][] nums = new int[][]{{4,8}, {1,6},{2,9}};
-        solve(nums);
+        solve1(nums);
     }
 
     public void solve(int[][] nums) {
@@ -93,18 +93,18 @@ public class Question1 {
         for (int i = 1; i < nums.length; i++) {
             if (last[1] > nums[i][0]) {
 
-                    total.add(new int[]{last[0], nums[i][0]-1});
+                total.add(new int[]{last[0], nums[i][0] - 1});
-                    condition.add(1);
+                condition.add(1);
-                    if (nums[i][1] < last[1]) {
+                if (nums[i][1] < last[1]) {
-                        total.add(new int[]{nums[i][0], nums[i][1]});
+                    total.add(new int[]{nums[i][0], nums[i][1]});
-                        condition.add(2);
+                    condition.add(2);
-                        last[0] = nums[i][1];
+                    last[0] = nums[i][1];
-                    } else {
+                } else {
-                        total.add(new int[]{nums[i][0], last[1]});
+                    total.add(new int[]{nums[i][0], last[1]});
-                        condition.add(2);
+                    condition.add(2);
-                        last[0] = last[1];
+                    last[0] = last[1];
-                        last[1] = nums[i][1];
+                    last[1] = nums[i][1];
-                    }
+                }
             } else {
                 total.add(new int[]{last[0], last[1]});
                 condition.add(1);
@@ -119,14 +119,66 @@ public class Question1 {
         for (int i = 0; i < total.size(); i++) {
             int[] ints = total.get(i);
             Integer condition1 = condition.get(i);
-            if(condition1==0){
+            if (condition1 == 0) {
-                result+=(ints[1]-ints[0]+1);
+                result += (ints[1] - ints[0] + 1);
-            }else if(condition1==1){
+            } else if (condition1 == 1) {
-                result+=(ints[1]-ints[0]+1)*3;
+                result += (ints[1] - ints[0] + 1) * 3;
-            }else {
+            } else {
-                result+=(ints[1]-ints[0]+1)*4;
+                result += (ints[1] - ints[0] + 1) * 4;
             }
         }
         System.out.println(result);
     }
+
+
+    /**
+     * 后来重写的情况:两个用例应该是对了
+     * @param nums
+     */
+    public void solve1(int[][] nums) {
+        Arrays.sort(nums, new Comparator<int[]>() {
+            @Override
+            public int compare(int[] o1, int[] o2) {
+                return o1[0] == o2[0] ? o1[1] - o2[1] : o1[0] - o2[0];
+            }
+        });
+
+
+        int[] last = nums[0];
+
+        int result = 0;
+
+        for (int i = 1; i < nums.length; i++) {
+            if (last[1] > nums[i][0]) {
+                if (nums[i][1] < last[0]) {
+                    //特殊情况直接continue
+                    continue;
+                } else if (nums[i][0] < last[0]) {
+                    nums[i][0] = last[0];//直接归入
+                }
+                //计算单任务部分
+                result += (nums[i][0] - last[0]) * 3;
+                //计算多任务部分
+                if (nums[i][1] < last[1]) {
+                    result += (nums[i][1] - nums[i][0] + 1) * 4;
+                    last[0] = nums[i][1] + 1;
+                } else {
+                    result += (last[1] - nums[i][0] + 1) * 4;
+                    last[0] = last[1] + 1;
+                    last[1] = nums[i][1];
+                }
+            } else {
+                //单任务部分
+                result += (last[1] - last[0] + 1) * 3;
+                //无任务部分
+                result += (nums[i][0] - last[1] - 1);
+                last = nums[i];
+            }
+        }
+
+        //最后加上单任务
+        result += (last[1] - last[0] + 1) * 3;
+
+        System.out.println(result);
+    }
 }