mininum_depth_of_binary_tree.go

package main

type TreeNode struct {
	Val   int
	Left  *TreeNode
	Right *TreeNode
}

func minDepth(root *TreeNode) int {
	stack := make([]*TreeNode, 0)
	if root == nil {
		return 0
	}
	stack = append(stack, root)
	res := 0
	for len(stack) > 0 {
		res++
		l := len(stack)
		for i := 0; i < l; i++ {
			if stack[i].Left == nil && stack[i].Right == nil {
				return res
			}
			if stack[i].Left != nil {
				stack = append(stack, stack[i].Left)
			}
			if stack[i].Right != nil {
				stack = append(stack, stack[i].Right)
			}

		}
		stack = stack[l:]
	}
	return res
}