add new files

Author: anakin

566. Reshape the Matrix.go

@@ -0,0 +1,23 @@
+package main
+
+func matrixReshape(nums [][]int, r int, c int) [][]int {
+	ret := make([][]int, r)
+	for k := range ret {
+		ret[k] = make([]int, c)
+	}
+	if len(nums) == 0 || r*c != len(nums)*len(nums[0]) {
+		return nums
+	}
+	rows, cols := 0, 0
+	for i := 0; i < len(nums); i++ {
+		for j := 0; j < len(nums[0]); j++ {
+			ret[rows][cols] = nums[i][j]
+			cols++
+			if cols == c {
+				rows++
+				cols = 0
+			}
+		}
+	}
+	return ret
+}

662. Maximum Width of Binary Tree.go

@@ -0,0 +1,36 @@
+package main
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+var ans int
+var left map[int]int
+
+func widthOfBinaryTree(root *TreeNode) int {
+	ans = 0
+	left = make(map[int]int)
+	dfs(root, 0, 0)
+	return ans
+}
+func dfs(root *TreeNode, depth, pos int) {
+	if root == nil {
+		return
+	}
+	if _, ok := left[depth]; !ok {
+		left[depth] = pos
+	}
+	ans = max(ans, pos-left[depth]+1)
+	dfs(root.Left, depth+1, 2*pos)
+	dfs(root.Right, depth+1, 2*pos+1)
+}
+
+func max(x, y int) int {
+	if x > y {
+		return x
+	}
+	return y
+
+}

766. Toeplitz Matrix.go

@@ -0,0 +1,12 @@
+package main
+
+func isToeplitzMatrix(matrix [][]int) bool {
+	for r := 0; r < len(matrix); r++ {
+		for c := 0; c < len(matrix[0]); c++ {
+			if r > 0 && c > 0 && matrix[r-1][c-1] != matrix[r][c] {
+				return false
+			}
+		}
+	}
+	return true
+}

771. Jewels and Stones.go

@@ -0,0 +1,17 @@
+package main
+
+func numJewelsInStones(J string, S string) int {
+	jstr := []byte(J)
+	sstr := []byte(S)
+	m := make(map[byte]bool)
+	for _, v := range jstr {
+		m[v] = true
+	}
+	num := 0
+	for _, v := range sstr {
+		if _, ok := m[v]; ok {
+			num++
+		}
+	}
+	return num
+}

867. Transpose Matrix.go

@@ -0,0 +1,16 @@
+package main
+
+func transpose(A [][]int) [][]int {
+	m := len(A)
+	n := len(A[0])
+	ans := make([][]int, n)
+	for k := range ans {
+		ans[k] = make([]int, m)
+	}
+	for r := 0; r < m; r++ {
+		for c := 0; c < n; c++ {
+			ans[c][r] = A[r][c]
+		}
+	}
+	return ans
+}