Mirror image of binary tree

subject

[ Simple 、 recursive ]

Answer key

The left and right subtrees of a commutative binary tree

function Mirror( pRoot ) {
    
    // Recursive export 
    if(pRoot === null){
    
       return pRoot;
       } else {
    
        [pRoot.left,pRoot.right] = [pRoot.right,pRoot.left]
    }
    Mirror(pRoot.left);
    Mirror(pRoot.right);
    return pRoot;
}

Supplementary knowledge

Answer template of binary tree

function traverse(TreeNode root){
    
    //  The former sequence traversal 
    traverse(root.left)
    //  In the sequence traversal 
    traverse(root.right)
    //  After the sequence traversal 
}

The central idea of recursion ：

• Consider exporting （ if part ）
• Process the current node
• Recursively process the next node

Recursive exit of binary tree problem , Generally include ：

// 1. Node is empty （ To the leaf node ）
pRoot === null

The article links : Image of binary tree [ The finger of the sword offer]
* Please quote from QW’s Blog！*