feat: 螺旋矩阵、公共祖先

src/leecode/java/No236.java

@@ -0,0 +1,37 @@
+package leecode.java;
+
+import leecode.tree.TreeNode;
+
+/**
+ * @author Wen
+ * @date 2025/6/19 20:48
+ */
+public class No236 {
+
+    private TreeNode result = null;
+    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
+        dfs(root, p, q);
+        return result;
+    }
+
+    public boolean dfs(TreeNode root, TreeNode p, TreeNode q) {
+        if (root == null) {
+            return false;
+        }
+        boolean lson = dfs(root.left, p, q);
+        boolean rson = dfs(root.right, p, q);
+        // 自己是公共祖先
+        if (root.val == p.val || root.val == q.val) {
+            if (lson || rson) {
+                result = root;
+            }
+            return true;
+        }
+        // 一般情况下的公共祖先，分别在该节点的左右子树
+        if (lson && rson) {
+            result = root;
+            return true;
+        }
+        return lson || rson;
+    }
+}

src/leecode/java/No54.java

@@ -0,0 +1,66 @@
+package leecode.java;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * @author Wen
+ * @date 2025/6/19 13:18
+ */
+public class No54 {
+
+    public List<Integer> spiralOrder(int[][] matrix) {
+        String a = "";
+        String.valueOf(a.charAt(1));
+        List<Integer> result = new ArrayList<>();
+        dfs(result, matrix, 0, 0, matrix.length, matrix[0].length);
+        return result;
+    }
+
+
+    public void dfs(List<Integer> result, int[][] matrix, int x, int y, int height, int width) {
+        if (height <= 0 || width <= 0) {
+            return;
+        }
+        // 单横边情况处理
+        if (height == 1) {
+            for (int i = x; i < x + width; i++) {
+                result.add(matrix[y][i]);
+            }
+            return;
+        }
+        // 单竖边情况处理
+        if (width == 1) {
+            for (int i = y; i < y + height; i++) {
+                result.add(matrix[i][x]);
+            }
+            return;
+        }
+        for (int i = x; i < x + width - 1; i++) {
+            result.add(matrix[y][i]);
+        }
+        for (int i = y; i < y + height - 1; i++) {
+            result.add(matrix[i][x + width - 1]);
+        }
+        for (int i = x + width - 1; i > x; i--) {
+            result.add(matrix[y + height - 1][i]);
+        }
+        for (int i = y + height - 1; i > y; i--) {
+            result.add(matrix[i][x]);
+        }
+        dfs(result, matrix, x + 1, y + 1, height - 2, width - 2);
+    }
+
+    public static void main(String[] args) {
+        No54 no54 = new No54();
+        int[][] matrix = {
+                {1, 2, 3},
+                {4, 5, 6},
+                {7, 8, 9}
+        };
+        System.out.println(no54.spiralOrder(matrix));
+    }
+
+}
+
+