题解 | #修剪叶子#

/**
 * struct TreeNode {
 *	int val;
 *	struct TreeNode *left;
 *	struct TreeNode *right;
 * };
 */
/**
 * 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 root TreeNode类 
 * @return TreeNode类
 */

bool ismid(struct TreeNode* root ){ // 判断是否是叶节点父节点
    if(root == NULL){
        return false;
    }
    if(root->left == NULL && root->right == NULL){
        return false;
    }
    if(root->left != NULL){
        if(root->left->left ==NULL && root->left->right == NULL){
            return true;
        }
    }
    if(root->right != NULL){
        if(root->right->left ==NULL && root->right->right == NULL){
            return true;
        }
    }
    return false;
}

struct TreeNode* pruneLeaves(struct TreeNode* root ) {
    if(ismid(root)){
        root = NULL;
    }
    else{
        if(root->left != NULL){
            root->left = pruneLeaves(root->left);
        }
        if(root->right != NULL){
            root->right = pruneLeaves(root->right);
        }
    }
    return root;
}