Add day19

Jongeun/Day19/212_WordSearchII.cpp

@@ -0,0 +1,130 @@
+#include <iostream>
+#include <vector>
+#include <string>
+
+using namespace std;
+
+class TrieNode
+{
+public:
+    TrieNode *children[26];
+    bool isEnd;
+
+    TrieNode()
+    {
+        for (int i = 0; i < 26; i++)
+        {
+            children[i] = nullptr;
+        }
+        isEnd = false;
+    }
+};
+
+class Trie
+{
+public:
+    TrieNode *root;
+
+    Trie()
+    {
+        root = new TrieNode();
+    }
+
+    bool Search(string word)
+    {
+        TrieNode *cur = root;
+        for (auto c : word)
+        {
+            if (cur->children[c - 'a'] == nullptr)
+            {
+                return false;
+            }
+
+            cur = cur->children[c - 'a'];
+        }
+
+        return cur->isEnd;
+    }
+};
+
+class Solution
+{
+public:
+    vector<string> findWords(vector<vector<char>> &board, vector<string> &words)
+    {
+        int m = board.size();
+        int n = board[0].size();
+        Trie *trie = new Trie();
+        vector<string> res;
+
+        for (int i = 0; i < 1; i++)
+        {
+            for (int j = 0; < 1; j++)
+            {
+                // construct the trie based on the board
+                constructTrie(board, trie->root, m, n, i, j);
+            }
+        }
+
+        // search
+        for (string &str : words)
+        {
+            if (trie->Search(str))
+            {
+                res.push_back(str);
+            }
+        }
+
+        return res;
+    }
+
+    void constructTrie(vector<vector<char>> &board, TrieNode *node, int m, int n, int i, int j)
+    {
+        if (i < 0 || i >= m || j < 0 || j >= n)
+        {
+            // previous node
+            node->isEnd = true;
+            return;
+        }
+
+        // already visited
+        if (board[i][j] == '#')
+        {
+            node->isEnd = true;
+            return;
+        }
+
+        char c = board[i][j];
+
+        if (node->children[c - 'a'] == nullptr)
+        {
+            TrieNode *temp = new TrieNode();
+            node->children[c - 'a'] = temp;
+        }
+
+        board[i][j] = '#';
+        constructTrie(board, node->children[c - 'a'], m, n, i - 1, j);
+        constructTrie(board, node->children[c - 'a'], m, n, i, j - 1);
+        constructTrie(board, node->children[c - 'a'], m, n, i, j + 1);
+        constructTrie(board, node->children[c - 'a'], m, n, i + 1, j);
+        board[i][j] = c;
+    }
+};
+
+int main()
+{
+    Solution sol;
+    vector<vector<char>> board = {{'o', 'a', 'a', 'n'},
+                                  {'e', 't', 'a', 'e'},
+                                  {'i', 'h', 'k', 'r'},
+                                  {'i', 'f', 'l', 'v'}};
+    vector<string> words = {"oath", "pea", "eat", "rain"};
+    vector<string> res = sol.findWords(board, words);
+
+    for (string &str : res)
+    {
+        cout << str << " ";
+    }
+
+    return 0;
+}

Jongeun/Day19/621_TaskScheduler.cpp

@@ -0,0 +1,69 @@
+class Solution
+{
+public:
+    // Structure of the condition
+    // for sorting the pair by its
+    // second elements
+    struct myComp
+    {
+        constexpr bool operator()(
+            pair<int, int> const &a,
+            pair<int, int> const &b)
+            const noexcept
+        {
+            return a.second > b.second;
+        }
+    };
+    int leastInterval(vector<char> &tasks, int n)
+    {
+        vector<bool> isInQueue(26);
+        vector<int> leftTasks(26);
+        int totalLeft{};
+        priority_queue<pair<int, int>, vector<pair<int, int>>, myComp> mq; // min heap
+
+        for (int i = 0; i < tasks.size(); i++)
+        {
+
+            leftTasks[tasks[i] - 'A']++;
+            totalLeft++;
+        }
+
+        int time = 1;
+        while (totalLeft > 0)
+        {
+            // Pop
+            if (!mq.empty() && (time - mq.top().second) > n)
+            {
+                int i = mq.top().first;
+                isInQueue[i] = false;
+                mq.pop();
+            }
+
+            // Push
+            // find the one with the most left and not in queue
+            // O(26)
+            int mostIndex = -1;
+            int most = 0;
+            for (int i = 0; i < leftTasks.size(); i++)
+            {
+                if (!isInQueue[i] && leftTasks[i] > most)
+                {
+                    most = leftTasks[i];
+                    mostIndex = i;
+                }
+            }
+
+            if (mostIndex != -1)
+            {
+                mq.push({mostIndex, time});
+                isInQueue[mostIndex] = true;
+                leftTasks[mostIndex]--;
+                totalLeft--;
+            }
+
+            time++;
+        }
+
+        return time - 1;
+    }
+};

Jongeun/Day19/79_WordSearch.cpp

@@ -0,0 +1,73 @@
+class Solution
+{
+public:
+    bool exist(vector<vector<char>> &board, string word)
+    {
+        bool isFind{false};
+
+        vector<vector<bool>> isPassed;
+
+        for (int i = 0; i < board.size(); i++)
+        {
+            vector<bool> temp;
+            for (int j = 0; j < board[i].size(); j++)
+            {
+                temp.push_back(false);
+            }
+            isPassed.push_back(temp);
+        }
+
+        for (int i = 0; i < board.size(); i++)
+        {
+            for (int j = 0; j < board[i].size(); j++)
+            {
+                _exist(board, isPassed, word, i, j, 0, isFind);
+            }
+        }
+
+        return isFind;
+    }
+
+    void _exist(vector<vector<char>> &board, vector<vector<bool>> &isPassed, string &word, int i, int j, int step, bool &isFind)
+    {
+        // bound checking
+        if (i < 0 || i >= board.size())
+        {
+            return;
+        }
+
+        if (j < 0 || j >= board[i].size())
+        {
+            return;
+        }
+
+        // safe bound
+
+        // is Already Passed?
+        if (isPassed[i][j])
+        {
+            return;
+        }
+
+        // found
+        if (word[step] == board[i][j])
+        {
+
+            if (step == word.size() - 1)
+            {
+                // end index
+                isFind = true;
+                return;
+            }
+
+            isPassed[i][j] = true;
+            // Not End index -> keep search(E,W,S,N)
+            _exist(board, isPassed, word, i - 1, j, step + 1, isFind);
+            _exist(board, isPassed, word, i, j - 1, step + 1, isFind);
+            _exist(board, isPassed, word, i, j + 1, step + 1, isFind);
+            _exist(board, isPassed, word, i + 1, j, step + 1, isFind);
+
+            isPassed[i][j] = false;
+        }
+    }
+};