https://www.acwing.com/problem/content/35/

今天做这题

java
class Solution {
    public boolean hasSubtree(TreeNode pRoot1, TreeNode pRoot2) {
         if(pRoot1 == null || pRoot2 == null) {
            return false;
        }
        
        return v(pRoot1,pRoot2) || hasSubtree(pRoot1.left,pRoot2) || hasSubtree(pRoot1.right,pRoot2);
    }
    
    private boolean v(TreeNode A,TreeNode B) {
        if(B == null) {
            return true;
        }
        
        if(A == null || A.val != B.val){
            return false;
        }
        
        return v(A.left,B.left) && v(A.right, B.right);
    }
}

go
/**
 * Definition for a binary tree node.
 * type TreeNode struct {
 *     Val int
 *     Left *TreeNode
 *     Right *TreeNode
 * }
 */
func hasSubtree(pRoot1 *TreeNode, pRoot2 *TreeNode) bool {
    if(pRoot2 == nil || pRoot1 == nil) {
        return false;
    }
    
    return V(pRoot1, pRoot2) || hasSubtree(pRoot1.Left, pRoot2) || hasSubtree(pRoot1.Right, pRoot2);
}


func V(A, B *TreeNode) bool {
    if(B == nil) {
        return true;
    }
    
    if(A == nil || A.Val != B.Val) {
        return false;
    }
    
    return V(A.Left, B.Left) && V(A.Right, B.Right);
}