二叉树的层次遍历

Posted 2022-12-13 Blocking The Sky

class Solution 
public:
    vector<vector<int>> levelOrder(TreeNode* root) 
        TreeNode* p;
        vector<vector<int>> result;
        if(root==NULL)
            return result;
        queue<TreeNode*> q;
        q.push(root);
        vector<int> level;
        while(!q.empty())
            int size;
            size=q.size();
            for(int i=0;i<size;i++)
                p=q.front();
                q.pop();
                level.push_back(p->val);
                if(p->left)
                    q.push(p->left);
                
                if(p->right)
                    q.push(p->right);
                
            
            result.push_back(level);
            vector<int>().swap(level);
        
        return result;
    
;
/*
void  LevelOrder(BiTree T)
    InitQueue(Q);
    BiTree p;
    EnQueue(Q,T);
    while(!IsEmpty(Q))
        DeQueue(Q,p);
        visit(p);
        if(p->lchild!==NULL)
            EnQueue(Q,p->lchild);
        
        if(p->rchile!=NULL)
            EnQueue(Q,p->rchild);
        
    

*/