https://leetcode.com/problems/subtree-of-another-tree

subtree-of-another-tree.go

/**
 * Definition for a binary tree node.
 * type TreeNode struct {
 *     Val int
 *     Left *TreeNode
 *     Right *TreeNode
 * }
 */
func isSubtree(s *TreeNode, t *TreeNode) bool {
    queue := []*TreeNode{s}
    
    for len(queue) > 0 {
        node := queue[0]
        queue = queue[1:]
        
        if isEquals(node, t) {
            return true
        }
        
        if node.Left != nil {
            queue = append(queue, node.Left)
        }
        
        if node.Right != nil {
            queue = append(queue, node.Right)
        }
    }
    
    return false
}

func isEquals(s, t *TreeNode) bool {
    if s == t {
        return true
    }
    
    if s == nil || t == nil {
        return false
    }
    
    return s.Val == t.Val && isEquals(s.Left, t.Left) && isEquals(s.Right, t.Right)
}