update

04-algrithm/09-build-tree/index.js

@@ -0,0 +1,59 @@
+// 广度优先创建二叉树
+const node = {
+    v: 1,
+    l: {
+        v: 2,
+    },
+    r: {
+        v: 3,
+    }
+}
+
+const tree = {
+
+}
+const max = 10
+const buildTree = (node, i) => {
+    if (i > max) return
+    node.v = i
+    node.l = buildTree({}, 2 * i)
+    node.r = buildTree({}, 2 * i + 1)
+    return node
+}
+buildTree(tree, 1)
+
+
+// 递归中序遍历函数
+function inorderTraversal(root) {
+    const res = []
+    const inorder = (root) => {
+        if (!root) {
+            return
+        }
+        res.push(root.v)
+        inorder(root.l)
+        inorder(root.r)
+    }
+    inorder(root)
+    return res
+}
+const res = inorderTraversal(tree)
+console.log('中序遍历', res)
+
+function postorderTraversal(root) {
+    const res = []
+    const inorder = (root) => {
+        if (!root) {
+            return
+        }
+        inorder(root.l)
+        inorder(root.r)
+        res.push(root.v)
+    }
+    inorder(root)
+    return res
+}
+
+// console.log('后续序遍历', postorderTraversal(tree))
+
+// console.log(JSON.stringify(tree, null, 4))

04-algrithm/10-spiral-text/index.js

@@ -0,0 +1,56 @@
+function spiralText(text) {
+    const rows = 5; // 矩阵的行数
+    const cols = 5; // 矩阵的列数
+    const matrix = new Array(rows);
+    for (let i = 0; i < rows; i++) {
+        matrix[i] = new Array(cols).fill(' ');
+    }
+    let direction = 0; // 初始方向（0表示向右，1表示向下，2表示向左，3表示向上）
+    let count = 0; // 用于记录已填写的字符数
+    let row = 0;
+    let col = 0;
+
+    for (let i = 0; i < text.length; i++) {
+        matrix[row][col] = text.charAt(i);
+        count++;
+
+        if (direction === 0) { // 向右移动
+            if (col < cols - 1 && matrix[row][col + 1] === ' ') {
+                col++;
+            } else {
+                direction = (direction + 1) % 4;
+                row++;
+            }
+        } else if (direction === 1) { // 向下移动
+            if (row < rows - 1 && matrix[row + 1][col] === ' ') {
+                row++;
+            } else {
+                direction = (direction + 1) % 4;
+                col--;
+            }
+        } else if (direction === 2) { // 向左移动
+            if (col > 0 && matrix[row][col - 1] === ' ') {
+                col--;
+            } else {
+                direction = (direction + 1) % 4;
+                row--;
+            }
+        } else { // 向上移动
+            if (row > 0 && matrix[row - 1][col] === ' ') {
+                row--;
+            } else {
+                direction = (direction + 1) % 4;
+                col++;
+            }
+        }
+    }
+
+    // 打印回型文字
+    for (let i = 0; i < rows; i++) {
+        console.log(matrix[i].join(' '));
+    }
+}
+
+// 测试示例
+const text = "12345678901234567890";
+spiralText(text);

04-algrithm/10-spiral-text/index2.js

@@ -0,0 +1,48 @@
+const len = 5
+const arr = new Array(5).fill().map(() => new Array(5).fill(' '));
+
+
+const str = '123456789012345'
+let direction = 0;  // 0: right, 1: down, 2: left, 3: up
+let row = 0;
+let col = 0;
+for (let i = 0; i < str.length; i++) {
+    arr[row][col] = str.charAt(i);
+    if (direction === 0) {
+        if (col < len - 1 && arr[row][col + 1] === ' ') {
+            col++;
+        } else {
+            direction = (direction + 1) % 4;
+            row++;
+        }
+    } else if (direction === 1) {
+        if (row < len - 1 && arr[row + 1][col] === ' ') {
+            row++;
+        } else {
+            direction = (direction + 1) % 4;
+            col--;
+        }
+
+    } else if (direction === 2) {
+        if (col > 0 && arr[row][col - 1] === ' ') {
+            col--;
+        } else {
+            direction = (direction + 1) % 4;
+            row--;
+        }
+    } else {
+        if (row > 0 && arr[row - 1][col] === ' ') {
+            row--;
+        } else {
+            direction = (direction + 1) % 4;
+            col++;
+        }
+    }
+}
+
+arr.forEach(item => {
+    console.log(item);
+})
+
+
+// console.log(JSON.stringify(arr, null, 2));

04-algrithm/10-spiral-text/index3.js

@@ -0,0 +1,50 @@
+const arr = new Array(5).fill().map(() => new Array(5).fill(' '));
+
+const str = '1234567890123456789012345'
+let direction = 0;  // 0: right, 1: down, 2: left, 3: up
+let row = 0;
+let col = 0;
+
+for (i = 0; i < str.length; i++) {
+    arr[row][col] = str[i];
+    if (direction === 0) {
+        if (col < 4 && arr[row][col + 1] === ' ') {
+            col++;
+        }
+        else {
+            direction = (direction + 1) % 4;
+            row++;
+        }
+    } else if (direction === 1) {
+        if (row < 4 && arr[row + 1][col] === ' ') {
+            row++;
+        }
+        else {
+            direction = (direction + 1) % 4;
+            col--;
+        }
+    } else if (direction === 2) {
+        if (col > 0 && arr[row][col - 1] === ' ') {
+            col--;
+        }
+        else {
+            direction = (direction + 1) % 4;
+            row--;
+        }
+    } else {
+        if (row > 0 && arr[row - 1][col] === ' ') {
+            row--;
+        }
+        else {
+            direction = (direction + 1) % 4;
+            col++;
+        }
+    }
+
+
+}
+
+
+arr.map(v => {
+    console.log(v.join(' '));
+})