旋转矩阵

Author: baxiang

236lowest-common-ancestor-of-a-binary-tree/main.go

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+package main
+
+func main() {
+	$END$
+}

257binary-tree-paths/main.go

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+package main
+
+func main() {
+	$END$
+}

4er-wei-shu-zu-zhong-de-cha-zhao-lcof/main.go

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+package main
+
+func main() {
+	$END$
+}

54spiral-matrix/main.go

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+package main
+
+import "fmt"
+
+func spiralOrder1(matrix [][]int) []int {
+	var res []int
+	if len(matrix)==0{
+		return res
+	}
+	row :=len(matrix)
+	col := len(matrix[0])
+	up :=0//上界
+	down :=row-1//下界
+	left :=0//左界
+	right :=col-1// 右界
+	total := row*col//总数
+	for {
+		// 从左到右
+		for i:=left;i<=right;i++{
+			res = append(res,matrix[up][i])
+		}
+		if len(res)==total{
+			break
+		}
+		up++// 上边界+1 向下移动一位
+		for i:=up;i<=down;i++{
+			res = append(res,matrix[i][right])
+		}
+		if len(res)==total{
+			break
+		}
+		right--
+		for i:=right;i>=left;i--{
+			res = append(res,matrix[down][i])
+		}
+		if len(res)==total{
+			break
+		}
+		down--
+		for i:=down;i>=up;i--{
+			res = append(res,matrix[i][left])
+		}
+		if len(res)==total{
+			break
+		}
+		left++
+	}
+	return res
+}
+
+
+func spiralOrder(matrix [][]int) []int {
+	var res []int
+	if len(matrix)==0{
+		return res
+	}
+	row :=len(matrix)
+	col := len(matrix[0])
+    up :=0//上界
+    down :=row-1//下界
+    left :=0//左界
+    right :=col-1// 右界
+    for {
+    	// 从左到右
+    	for i:=left;i<=right;i++{
+    		res = append(res,matrix[up][i])
+		}
+		up++// 上边界+1 向下移动一位
+		if up>down{
+			break
+		}
+		// 从上到下
+		for i:=up;i<=down;i++{
+			res = append(res,matrix[i][right])
+		}
+		// 右边界移动
+		right--
+		if right<left{
+			break
+		}
+		//从右到左
+		for i:=right;i>=left;i--{
+			res = append(res,matrix[down][i])
+		}
+		//下边界向上移动一位
+		down--
+		if down<up{
+			break
+		}
+        // 从下到上
+		for i:=down;i>=up;i--{
+			res = append(res,matrix[i][left])
+		}
+        // 左边界向右移动一位
+		left++
+		if left>right{
+			break
+		}
+	}
+   return res
+}
+
+
+func main() {
+	fmt.Println(spiralOrder1([][]int{
+		{1, 2, 3 },
+	{ 4, 5, 6 },
+	{ 7, 8, 9 },
+	}))
+
+	fmt.Println(spiralOrder1([][]int{
+		{1, 2, 3, 4},
+	{5, 6, 7, 8},
+	{9, 10, 11, 12},
+	}))
+}

5ti-huan-kong-ge-lcof/main.go

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+package main
+
+func main() {
+	$END$
+}

7zhong-jian-er-cha-shu-lcof/main.go

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+package main
+
+import "fmt"
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func buildTree(preorder []int, inorder []int) *TreeNode {
+	if len(preorder) == 0 {
+		return nil
+	}
+	rootIdx := 0
+	for i := range inorder {
+		if inorder[i] == preorder[0] {
+			rootIdx = i
+			break
+		}
+	}
+	root := &TreeNode{Val: preorder[0]}
+	root.Left = buildTree(preorder[1:rootIdx+1], inorder[:rootIdx])
+	root.Right = buildTree(preorder[rootIdx+1:], inorder[rootIdx+1:])
+	return root
+}
+func printTree(root *TreeNode) {
+	if root == nil {
+		return
+	}
+	fmt.Println(root.Val)
+	printTree(root.Left)
+	printTree(root.Right)
+}
+
+func main() {
+	r := buildTree([]int{3, 9, 20, 15, 7}, []int{9, 3, 15, 20, 7})
+	printTree(r)
+}