Add day16

Jongeun/Day16/211_DesignAddandSearchWordsDataStructure.cpp

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+
+struct TrieNode
+{
+    TrieNode *ChildNode[26];
+    bool isEnd;
+    TrieNode()
+    {
+        for (int i = 0; i < 26; i++)
+        {
+            ChildNode[i] = nullptr;
+        }
+        isEnd = false;
+    }
+};
+
+class WordDictionary
+{
+public:
+    WordDictionary()
+    {
+        root = new TrieNode();
+    }
+
+    void addWord(string word)
+    {
+        TrieNode *cur = root;
+        for (auto c : word)
+        {
+            if (cur->ChildNode[c - 'a'] == nullptr)
+            {
+                TrieNode *temp = new TrieNode();
+                cur->ChildNode[c - 'a'] = temp;
+                cur = temp;
+            }
+            else
+            {
+                cur = cur->ChildNode[c - 'a'];
+            }
+        }
+
+        cur->isEnd = true;
+    }
+
+    bool search(string word)
+    {
+        TrieNode *cur = root;
+        return _search(root, word);
+    }
+
+    bool _search(TrieNode *node, string word)
+    {
+        if (word.empty())
+        {
+            return node->isEnd == true;
+        }
+
+        TrieNode *cur = node;
+        for (int i = 0; i < word.size(); i++)
+        {
+            if (word[i] == '.')
+            {
+                bool searched = false;
+                for (int j = 0; j < 26; j++)
+                {
+                    if (cur->ChildNode[j] != nullptr)
+                    {
+                        searched = _search(cur->ChildNode[j], word.substr(i + 1));
+                    }
+                    if (searched == true)
+                    {
+                        return true;
+                    }
+                }
+
+                return false;
+            }
+            else if (cur->ChildNode[word[i] - 'a'] == nullptr)
+            {
+                return false;
+            }
+            else
+            {
+                cur = cur->ChildNode[word[i] - 'a'];
+            }
+        }
+
+        return cur->isEnd == true;
+    }
+
+private:
+    TrieNode *root;
+};
+
+/**
+ * Your WordDictionary object will be instantiated and called as such:
+ * WordDictionary* obj = new WordDictionary();
+ * obj->addWord(word);
+ * bool param_2 = obj->search(word);
+ */

Jongeun/Day16/46_Permutations.cpp

@@ -0,0 +1,37 @@
+class Solution
+{
+public:
+    vector<vector<int>> permute(vector<int> &nums)
+    {
+        vector<vector<int>> res;
+        vector<int> ans;
+        unordered_map<int, int> m;
+        for (auto i : nums)
+        {
+            m[i] = 1;
+        }
+        _permute(res, ans, m);
+        return res;
+    }
+
+    void _permute(vector<vector<int>> &res, vector<int> &ans, unordered_map<int, int> &m)
+    {
+        if (ans.size() == m.size())
+        {
+            res.push_back(ans);
+            return;
+        }
+
+        for (auto &it : m)
+        {
+            if (it.second == 1)
+            {
+                it.second--;
+                ans.push_back(it.first);
+                _permute(res, ans, m);
+                ans.pop_back();
+                it.second++;
+            }
+        }
+    }
+};

Jongeun/Day16/973_KClosestPointstoOrigin.cpp

@@ -0,0 +1,24 @@
+class Solution
+{
+public:
+    vector<vector<int>> kClosest(vector<vector<int>> &points, int k)
+    {
+        priority_queue<pair<double, vector<int>>, vector<pair<double, vector<int>>>, std::greater<pair<double, vector<int>>>> pq; // min heap
+        vector<vector<int>> result;
+        for (auto &v : points)
+        {
+            double origin = sqrt(pow(v[0], 2) + pow(v[1], 2));
+            pq.push({origin, v});
+        }
+
+        while (k > 0)
+        {
+            auto p = pq.top();
+            pq.pop();
+            result.push_back(p.second);
+            k--;
+        }
+
+        return result;
+    }
+};