Added Design HashMap

CMakeLists.txt

@@ -1305,4 +1305,15 @@ add_executable(MaximumTwinSumOfALinkedList
 target_link_libraries(
         MaximumTwinSumOfALinkedList
         GTest::gtest_main
+)
+
+# Design HashMap
+add_executable(DesignHashMap
+        Easy/DesignHashMap/include/solution.hpp
+        Easy/DesignHashMap/tests/test.cpp
+)
+
+target_link_libraries(
+        DesignHashMap
+        GTest::gtest_main
 )

Easy/DesignHashMap/include/solution.hpp

@@ -0,0 +1,49 @@
+#pragma once
+
+#include <list>
+#include <vector>
+#include <iostream>
+#include <algorithm>
+#include <gtest/gtest.h>
+
+class MyHashMap {
+public:
+    MyHashMap() = default;
+
+    static auto hash(const int32_t x) -> int32_t {
+        return (2 * x + 97) % 30011;
+    }
+
+    auto put(const int32_t key, const int32_t value) -> void {
+        int32_t i = hash(key);
+        for (auto &[k, v] : _table[i]) {
+            if (key == k) {
+                v = value;
+                return;
+            }
+        }
+        _table[i].emplace_back(key, value);
+    }
+
+    auto get(const int32_t key) -> int32_t {
+        int32_t i = hash(key);
+        for (auto &[k, v]: _table[i]) {
+            if (k == key) return v;
+        }
+        return -1;
+    }
+
+    auto remove(const int32_t key) -> void {
+        int32_t i = hash(key);
+        for (auto it = _table[i].begin();
+            it != _table[i].end(); ++it) {
+            if ((*it).first == key) {
+                _table[i].erase(it);
+                return;
+            }
+        }
+    }
+
+private:
+    std::list<std::pair<int32_t,int32_t>> _table[30011];
+};

Easy/DesignHashMap/tests/test.cpp

@@ -0,0 +1,15 @@
+#include "../include/solution.hpp"
+
+auto main() -> int {
+    MyHashMap *myHashMap = new MyHashMap();
+    myHashMap->put(1, 1);
+    myHashMap->put(2, 2);
+    myHashMap->get(1);
+    myHashMap->get(3);
+    myHashMap->put(2, 1);
+    myHashMap->get(2);
+    myHashMap->remove(2);
+    myHashMap->get(2);
+
+    return 0;
+}

Medium/MaximumTwinSumOfALinkedList/include/solution.hpp

@@ -13,8 +13,26 @@ struct ListNode {
 class Solution {
 public:
     static auto pair_sum(ListNode *head) -> int32_t {
+        if (head->next == nullptr) return head->value;
+        if (head->next->next == nullptr) {
+            return head->value + head->next->value;
+        }
 
+
+    }
+
+    static auto insert(ListNode **head_ref,
+                       const int32_t new_value) -> void {
+        auto *node = new ListNode();
+        node->value = new_value;
+        node->next = (*head_ref);
+        (*head_ref) = node;
     }
 
-    static auto insert(ListNode **head_ref)
+    static auto print(ListNode *head) -> void {
+        while (head != nullptr) {
+            std::cout << head->value << ' ';
+            head = head->next;
+        }
+    }
 };