zoukankan      html  css  js  c++  java
  • 113.Path Sum II

    class Solution {
    public:
        vector<vector<int> > pathSum(TreeNode *root, int sum) {
            vector<vector<int>> res;
            vector<int> out;
            helper(root, sum, out, res);
            return res;
        }
        void helper(TreeNode* node, int sum, vector<int>& out, vector<vector<int>>& res) {
            if (!node) return;
            out.push_back(node->val);
            if (sum == node->val && !node->left && !node->right) {
                res.push_back(out);
            }
            helper(node->left, sum - node->val, out, res);
            helper(node->right, sum - node->val, out, res);
            out.pop_back();
        }
    };
    
    class Solution {
    public:
        vector<vector<int> > pathSum(TreeNode *root, int sum) {
            vector<vector<int>> res;
            vector<TreeNode*> s;
            TreeNode *cur = root, *pre = NULL;
            int val = 0;
            while (cur || !s.empty()) {
                while (cur) {
                    s.push_back(cur);
                    val += cur->val;
                    cur = cur->left;
                }
                cur = s.back(); 
                if (!cur->left && !cur->right && val == sum) {
                    vector<int> v;
                    for (auto it : s) {
                        v.push_back(it->val);
                    }
                    res.push_back(v);
                }
                if (cur->right && cur->right != pre) cur = cur->right;
                else {
                    pre = cur;
                    val -= cur->val;
                    s.pop_back();
                    cur = NULL;
                }
            }
            return res;
        }
    };
    
  • 相关阅读:
    汤姆大叔的博客
    ajax
    兼容谷歌的光标居中写法
    浅谈服务治理与微服务
    Java线程面试题合集(含答案)
    java设计模式之装饰者模式
    java集合类详解
    java线程-看这一篇就够了
    javaIO详解
    java反射详解
  • 原文地址:https://www.cnblogs.com/smallredness/p/10677035.html
Copyright © 2011-2022 走看看