add new solutions

solutions/1/q100/solution.go

@@ -0,0 +1,27 @@
+package q100
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func traverse(p, q *TreeNode) bool {
+	if p == nil && q == nil {
+		return true
+	}
+	if p == nil || q == nil {
+		return false
+	}
+	if p.Val != q.Val {
+		return false
+	}
+	return traverse(p.Left, q.Left) &&
+		traverse(p.Right, q.Right)
+}
+
+func isSameTree(p *TreeNode, q *TreeNode) bool {
+	return traverse(p, q)
+}
+
+var _ = isSameTree

solutions/1/q101/solution.go

@@ -0,0 +1,27 @@
+package q101
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func traverse(left, right *TreeNode) bool {
+	if left == nil && right == nil {
+		return true
+	}
+	if left == nil || right == nil {
+		return false
+	}
+	if left.Val != right.Val {
+		return false
+	}
+	return traverse(left.Left, right.Right) &&
+		traverse(left.Right, right.Left)
+}
+
+func isSymmetric(root *TreeNode) bool {
+	return traverse(root.Left, root.Right)
+}
+
+var _ = isSymmetric

solutions/1/q112/solution.go

@@ -0,0 +1,26 @@
+package q112
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func traverse(node *TreeNode, tgtSum, curSum int) bool {
+	if node == nil {
+		return false
+	}
+
+	sum := curSum + node.Val
+	if node.Left == nil && node.Right == nil && sum == tgtSum {
+		return true
+	}
+	return traverse(node.Left, tgtSum, sum) ||
+		traverse(node.Right, tgtSum, sum)
+}
+
+func hasPathSum(root *TreeNode, targetSum int) bool {
+	return traverse(root, targetSum, 0)
+}
+
+var _ = hasPathSum