From 6320272406baa79c38f3ddd3ec8f8bc0848517f2 Mon Sep 17 00:00:00 2001 From: whaifree <49432110+whaibetter@users.noreply.github.com> Date: Sun, 28 Jul 2024 22:04:52 +0800 Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=E4=BA=86LeetCode=E9=A2=98?= =?UTF-8?q?=E7=9B=AE=E8=A7=A3=E7=AD=94=EF=BC=8C=E5=8C=85=E6=8B=AC216?= =?UTF-8?q?=E3=80=81222=E3=80=81232=E3=80=81236=E3=80=81257=E3=80=81347?= =?UTF-8?q?=E3=80=8177=E3=80=8194=E3=80=81101=E3=80=81102=E3=80=81105?= =?UTF-8?q?=E3=80=81110=E9=A2=98=E3=80=82?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../redo/redo_all_240721/LeetCode101.java | 35 ++++++++++ .../redo/redo_all_240721/LeetCode102.java | 68 +++++++++++++++++++ .../redo/redo_all_240721/LeetCode105.java | 64 +++++++++++++++++ .../redo/redo_all_240721/LeetCode110.java | 39 +++++++++++ .../redo/redo_all_240721/LeetCode216.java | 48 +++++++++++++ .../redo/redo_all_240721/LeetCode222.java | 46 +++++++++++++ .../redo/redo_all_240721/LeetCode232.java | 67 ++++++++++++++++++ .../redo/redo_all_240721/LeetCode236.java | 34 ++++++++++ .../redo/redo_all_240721/LeetCode257.java | 56 +++++++++++++++ .../redo/redo_all_240721/LeetCode347.java | 46 +++++++++++++ .../redo/redo_all_240721/LeetCode77.java | 50 ++++++++++++++ .../redo/redo_all_240721/LeetCode94.java | 58 ++++++++++++++++ 12 files changed, 611 insertions(+) create mode 100644 src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode101.java create mode 100644 src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode102.java create mode 100644 src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode105.java create mode 100644 src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode110.java create mode 100644 src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode216.java create mode 100644 src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode222.java create mode 100644 src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode232.java create mode 100644 src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode236.java create mode 100644 src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode257.java create mode 100644 src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode347.java create mode 100644 src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode77.java create mode 100644 src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode94.java diff --git a/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode101.java b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode101.java new file mode 100644 index 0000000..d8e9456 --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode101.java @@ -0,0 +1,35 @@ +package cn.whaifree.redo.redo_all_240721; + +import cn.whaifree.leetCode.model.TreeNode; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/7/28 0:16 + * @注释 + */ +public class LeetCode101 { + + public static void main(String[] args) { + System.out.println("hello world"); + System.out.println(isSymmetric(TreeNode.constructTree(new Integer[]{1, 2, 2, 3, 1, 4, 3}))); + } + public static boolean isSymmetric(TreeNode root) { + return isSymmetric(root, root); + } + + private static boolean isSymmetric(TreeNode p, TreeNode q) { + if (p == null && q == null) { + return true; + } + if (p == null || q == null) { + return false; + } + if (p.val != q.val) { + return false; + } + boolean one = isSymmetric(p.right, q.left); + boolean two = isSymmetric(p.left, q.right); + return one && two; + } +} diff --git a/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode102.java b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode102.java new file mode 100644 index 0000000..038bffb --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode102.java @@ -0,0 +1,68 @@ +package cn.whaifree.redo.redo_all_240721; + +import cn.whaifree.leetCode.model.TreeNode; + +import java.util.*; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/7/25 22:45 + * @注释 + */ +public class LeetCode102 { + public static void main(String[] args) { + + TreeNode treeNode = TreeNode.constructTreeByArray(3, 9, 20, null, null, 15, 7); + for (List integers : levelOrder1(treeNode)) { + System.out.println(integers); + } + } + + public static List> levelOrder(TreeNode root) { + + List> res = new ArrayList<>(); + if (root == null) { + return res; + } + Deque deque = new LinkedList<>(); + deque.add(root); + while (!deque.isEmpty()) { + int size = deque.size(); + List list = new ArrayList<>(); + for (int i = 0; i < size; i++) { + TreeNode pop = deque.pop(); + list.add(pop.val); + if (pop.left != null) { + deque.add(pop.left); + } + if (pop.right != null) { + deque.add(pop.right); + } + } + res.add(list); + } + + + return res; + } + + public static List> levelOrder1(TreeNode root) { + List> res = new ArrayList<>(); + level(root, 0, res); + return res; + } + + public static void level(TreeNode root, int inLevel, List> res) { + if (root == null) { + return; + } + if (res.size() == inLevel) { + res.add(new ArrayList<>()); + } + res.get(inLevel).add(root.val); + level(root.left, inLevel + 1, res); + level(root.right, inLevel + 1, res); + } + +} diff --git a/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode105.java b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode105.java new file mode 100644 index 0000000..3238bfc --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode105.java @@ -0,0 +1,64 @@ +package cn.whaifree.redo.redo_all_240721; + +import cn.whaifree.leetCode.model.TreeNode; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/7/28 18:31 + * @注释 + */ +public class LeetCode105 { + + public static void main(String[] args) { +// int[] preorder = {3, 9, 20, 15, 7}; +// int[] inorder = {9, 3, 15, 20, 7}; +// TreeNode root = buildTree(preorder, inorder); +// root.printTree(); +// +// TreeNode treeNode = buildTree(new int[]{1}, new int[]{1}); +// TreeNode.printTree(treeNode); + + buildTree(new int[]{1,2,3}, new int[]{3,2,1}).printTree(); + } + + /** + * + * + * @param preorder {3, 9, 20, 15, 7} + * @param inorder {9, 3, 15, 20, 7} + * @return + */ + public static TreeNode buildTree(int[] preorder, int[] inorder) { + return build(preorder, inorder, 0, preorder.length - 1, 0, inorder.length - 1); + } + + public static TreeNode build(int[] preorder, int[] inorder, int preStart, int preEnd, int inStart, int inEnd) { + if (preStart > preEnd) { + return null; + } + if (preStart == preEnd) { + return new TreeNode(preorder[preStart]); + } + if (inStart == inEnd) { + return new TreeNode(inorder[inStart]); + } + + // 前序中的第一个 + int want = preorder[preStart]; + // 在中序中找到分界的位置 + int inorderIndex = 0; + for (int i = inStart; i <= inEnd; i++) { + if (inorder[i] == want) { + inorderIndex = i; + break; + } + } + // 这个节点中序的左边有几个节点 + int leftInorderLen = inorderIndex - inStart; + TreeNode node = new TreeNode(want); + node.left = build(preorder, inorder, preStart + 1, preStart + leftInorderLen, inStart, inorderIndex - 1); + node.right = build(preorder, inorder, preStart + leftInorderLen + 1, preEnd, inorderIndex + 1, inEnd); + return node; + } +} diff --git a/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode110.java b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode110.java new file mode 100644 index 0000000..62515c7 --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode110.java @@ -0,0 +1,39 @@ +package cn.whaifree.redo.redo_all_240721; + +import cn.whaifree.leetCode.model.TreeNode; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/7/28 0:23 + * @注释 + */ +public class LeetCode110 { + + public static void main(String[] args) { + + TreeNode treeNode = TreeNode.constructTreeByArray(1, 2, 2, 3, 3, null, null, 4, 4); +// System.out.println(isBalanced(treeNode)); + System.out.println(isBalanced(TreeNode.constructTreeByArray(1,2,2,3,null,null,3,4,null,null,4))); + } + public static boolean isBalanced(TreeNode root) { + if (root == null) { + return true; + } + return level(root) != -1; + } + + public static int level(TreeNode root) { + if (root == null) { + return 0; + } + int left = level(root.left); + if (left==-1) return -1; + int right = level(root.right); + if (right==-1) return -1; + if (Math.abs(left - right) > 1) { + return -1; + } + return Math.max(left, right) + 1; + } +} diff --git a/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode216.java b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode216.java new file mode 100644 index 0000000..990cc9c --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode216.java @@ -0,0 +1,48 @@ +package cn.whaifree.redo.redo_all_240721; + +import java.util.ArrayList; +import java.util.List; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/7/28 21:46 + * @注释 + */ +public class LeetCode216 { + public static void main(String[] args) { + System.out.println(combinationSum3(9, 45)); + } + static List> res = new ArrayList<>(); + static List path = new ArrayList<>(); + static int nowSum = 0; + public static List> combinationSum3(int k, int n) { + circle(k, n, 1); + return res; + } + + public static void circle(int k, int n, int start) { + if (nowSum == n && path.size() == k) { + res.add(new ArrayList<>(path)); + return; + } + + for (int i = start; i <= 9; i++) { + /** + * nowSum + i > n + * path.size+9-i>k + */ + if (nowSum + i > n) { + break; + } + if ((9 - i + 1) < k - path.size()) { + break; + } + nowSum += i; + path.add(i); + circle(k, n, i + 1); + path.remove(path.size() - 1); + nowSum -= i; + } + } +} diff --git a/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode222.java b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode222.java new file mode 100644 index 0000000..6668d0e --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode222.java @@ -0,0 +1,46 @@ +package cn.whaifree.redo.redo_all_240721; + +import cn.whaifree.leetCode.model.TreeNode; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/7/28 19:40 + * @注释 + */ +public class LeetCode222 { + public static void main(String[] args) { + System.out.println(countNodes(TreeNode.constructTreeByArray(1, 2, 3, 4, 5, 6))); + } + + public static int countNodes(TreeNode root) { + if (root == null) { + return 0; + } + return count(root); + } + + public static int count(TreeNode root) { + if (root == null) { + return 0; + } + + TreeNode i = root; + int leftDepth = 0; + while (i.left != null) { + i = i.left; + leftDepth++; + } + i = root; + int rightDepth = 0; + while (i.right != null) { + i = i.right; + rightDepth++; + } + if (leftDepth == rightDepth) { + return (2 << leftDepth) - 1; + }else { + return count(root.left) + count(root.right) + 1; + } + } +} diff --git a/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode232.java b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode232.java new file mode 100644 index 0000000..457e035 --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode232.java @@ -0,0 +1,67 @@ +package cn.whaifree.redo.redo_all_240721; + +import java.util.Deque; +import java.util.LinkedList; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/7/24 22:17 + * @注释 + */ +public class LeetCode232 { + + public static void main(String[] args) { + MyQueue myQueue = new MyQueue(); + myQueue.push(1); // queue is: [1] + myQueue.push(2); // queue + System.out.println(myQueue.peek()); + System.out.println(myQueue.pop()); + System.out.println(myQueue.empty()); + System.out.println(myQueue.pop()); + System.out.println(myQueue.empty()); + } + + static class MyQueue { + + Deque stack1; + Deque stack2; + + public MyQueue() { + stack1 = new LinkedList<>(); + stack2 = new LinkedList<>(); + } + + public void push(int x) { + stack1.push(x); + } + + public int pop() { + while (stack1.size() > 1) { + stack2.push(stack1.pop()); + } + int res = stack1.pop(); + while (!stack2.isEmpty()) { + stack1.push(stack2.pop()); + } + return res; + } + + public int peek() { + while (stack1.size() > 1) { + stack2.push(stack1.pop()); + } + int res = stack1.pop(); + stack2.push(res); + while (!stack2.isEmpty()) { + stack1.push(stack2.pop()); + } + return res; + } + + public boolean empty() { + return stack1.isEmpty(); + } + } + +} diff --git a/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode236.java b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode236.java new file mode 100644 index 0000000..c71d376 --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode236.java @@ -0,0 +1,34 @@ +package cn.whaifree.redo.redo_all_240721; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/7/28 20:43 + * @注释 + */ + +import cn.whaifree.leetCode.model.TreeNode; + +public class LeetCode236 { + public static void main(String[] args) { + TreeNode treeNode = TreeNode.constructTreeByArray(3, 5, 1, 6, 2, 0, 8, null, null, 7, 4); + lowestCommonAncestor(treeNode, new TreeNode(6), new TreeNode(4)).printTree(); + } + public static TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) { + if (root == null || root.val == p.val || root.val == q.val) { + return root; + } + TreeNode right = lowestCommonAncestor(root.right, p, q); + TreeNode left = lowestCommonAncestor(root.left, p, q); + if (right == null && left == null) { + return null; + } + if (right != null && left != null) { + return root; + } if (right != null) { + return right; + } else { + return left; + } + } +} diff --git a/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode257.java b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode257.java new file mode 100644 index 0000000..6595751 --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode257.java @@ -0,0 +1,56 @@ +package cn.whaifree.redo.redo_all_240721; + +import cn.whaifree.leetCode.model.TreeNode; + +import java.util.ArrayList; +import java.util.List; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/7/28 0:32 + * @注释 + */ +public class LeetCode257 { + public static void main(String[] args) { + TreeNode treeNode = TreeNode.constructTreeByArray(3, 9, 20, null, null, 15, 7); + for (String binaryTreePath : binaryTreePaths(treeNode)) { + System.out.println(binaryTreePath); + } + for (String binaryTreePath : binaryTreePaths(TreeNode.constructTreeByArray(1,2,3,null,null,4,5))) { + System.out.println(binaryTreePath); + } + } + + public static List binaryTreePaths(TreeNode root) { + List res = new ArrayList<>(); + List path = new ArrayList<>(); + search(root, res, path); + return res; + } + + public static void search(TreeNode root,List res, List path) { + if (root == null) { + return; + } + path.add(root.val); + if (root.left == null && root.right == null) { + int val = root.val; + StringBuilder stringBuilder = new StringBuilder(); + for (int i = 0; i < path.size() - 1; i++) { + stringBuilder.append(path.get(i)).append("->"); + } + stringBuilder.append(val); + res.add(stringBuilder.toString()); + } + if (root.right != null) { + search(root.right, res, path); + } + if (root.left != null) { + search(root.left, res, path); + } + path.remove(path.size() - 1); + } + + +} diff --git a/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode347.java b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode347.java new file mode 100644 index 0000000..5c09548 --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode347.java @@ -0,0 +1,46 @@ +package cn.whaifree.redo.redo_all_240721; + +import java.util.*; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/7/24 22:23 + * @注释 + */ +public class LeetCode347 { + public static void main(String[] args) { + int[] nums = {1,1,1,2,2,3}; + int k = 2; + int[] ints = topKFrequent(nums, k); + System.out.println(Arrays.toString(ints)); + } + + public static int[] topKFrequent(int[] nums, int k) { + Map map = new HashMap<>(); + for (int num : nums) { + map.put(num, map.getOrDefault(num, 0) + 1); + } + + PriorityQueue priorityQueue = new PriorityQueue( + new Comparator() { + @Override + public int compare(Integer o1, Integer o2) { + if (map.get(o1) > map.get(o2)) { + return -1; + }else { + return 1; + } + } + } + ); + + priorityQueue.addAll(map.keySet()); + + ArrayList res = new ArrayList<>(); + for (int i = 0; i < k; i++) { + res.add(priorityQueue.poll()); + } + return res.stream().mapToInt(Integer::intValue).toArray(); + } +} diff --git a/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode77.java b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode77.java new file mode 100644 index 0000000..ff3c84c --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode77.java @@ -0,0 +1,50 @@ +package cn.whaifree.redo.redo_all_240721; + +import java.util.ArrayList; +import java.util.List; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/7/28 20:26 + * @注释 + */ +public class LeetCode77 +{ + + public static void main(String[] args) + { + int n = 4; + int k = 2; + System.out.println(new LeetCode77().combine(n, k)); + } + + List> res = new ArrayList<>(); + List path = new ArrayList<>(); + public List> combine(int n, int k) + { + circle(n, 1, k); + return res; + } + + public void circle(int n, int start, int k) { + if (path.size() == k) { + res.add(new ArrayList<>(path)); + return; + } + /** + * n start k i + * 能够提供的数 n-i + * 还需要的数 k - path.size + */ + for (int i = start; i <= n; i++) { + // 剪枝 + if (n - i < k - path.size() - 1) { + break; + } + path.add(i); + circle(n, i + 1, k); + path.remove(path.size() - 1); + } + } +} diff --git a/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode94.java b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode94.java new file mode 100644 index 0000000..093f682 --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_all_240721/LeetCode94.java @@ -0,0 +1,58 @@ +package cn.whaifree.redo.redo_all_240721; + +import cn.whaifree.leetCode.model.TreeNode; + +import java.util.Deque; +import java.util.LinkedList; +import java.util.List; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/7/24 22:37 + * @注释 + */ +public class LeetCode94 { + + + public static void main(String[] args) { + TreeNode treeNode = TreeNode.constructTreeByArray(); + List integers = inorderTraversal(treeNode); + for (Integer integer : integers) { + System.out.println(integer); + } + } + + + /** + * + * @param root + * @return + */ + public static List inorderTraversal(TreeNode root) { + + List res = new LinkedList<>(); + if (root == null) { + return res; + } + Deque stack = new LinkedList<>(); + stack.add(root); + while (!stack.isEmpty()) { + TreeNode pop = stack.pop(); + if (pop != null) { + if (pop.right != null) { + stack.push(pop.right); + } + stack.push(pop); + stack.push(null); + if (pop.left != null) { + stack.push(pop.left); + } + }else { + res.add(stack.pop().val); + } + + } + return res; + } +}