题解 | #树的子结构#

package main
import . "nc_tools"
/*
 * type TreeNode struct {
 *   Val int
 *   Left *TreeNode
 *   Right *TreeNode
 * }
 */

/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 * 
 * @param pRoot1 TreeNode类 
 * @param pRoot2 TreeNode类 
 * @return bool布尔型
*/
func isSubTree(root1 *TreeNode, root2 *TreeNode) bool {
    if root2 == nil {
        return true
    }
    if root1 == nil {
        return false
    }
    if root1.Val != root2.Val {
        return false
    }
    return isSubTree(root1.Left, root2.Left) && isSubTree(root1.Right, root2.Right)
}
func HasSubtree( pRoot1 *TreeNode ,  pRoot2 *TreeNode ) bool {
    // write code here
    if pRoot1 == nil || pRoot2 == nil {
        return false
    }
    res := false
    if pRoot1.Val == pRoot2.Val {
        res = isSubTree(pRoot1, pRoot2)
    }
    if !res {
        res = HasSubtree(pRoot1.Left, pRoot2)
    }
    if !res {
        res = HasSubtree(pRoot1.Right, pRoot2)
    }
    return res
}