返回和为目标值的二叉树的路径

Posted 2022-02-08 _BitterSweet

/*
struct TreeNode 
	int val;
	struct TreeNode *left;
	struct TreeNode *right;
	TreeNode(int x) :
			val(x), left(NULL), right(NULL) 
	
;*/
class Solution 
public:
    vector<vector<int> > result;
    void compare(vector<int>& path,TreeNode *root,int expectNumber,int sum)
    
        sum += root->val;
        if(sum == expectNumber && root->left == NULL && root->right == NULL)
        
            result.push_back(path);
            return ;
        
        
        if(root->left)
        
            path.push_back(root->left->val);
            compare(path,root->left,expectNumber,sum);
            path.pop_back();             //没达到目标，就弹出
            
        
        if(root->right)
        
            path.push_back(root->right->val);
            compare(path,root->right,expectNumber,sum);
            path.pop_back();             //没达到目标就弹出
            
        
    
    
    vector<vector<int> > FindPath(TreeNode* root,int expectNumber) 
        if(root == NULL)
        
            return result;
        
        vector<int> path;
        path.push_back(root->val);
        compare(path,root,expectNumber,0);
        return result;

    
;