From abdd59bf6a5a2f123f8e124e5fdd939771a110c4 Mon Sep 17 00:00:00 2001
From: kr0st <kr0st@bioreactor.me>
Date: Mon, 1 Dec 2025 22:36:44 +0100
Subject: [PATCH] Added accepted solutions for leetcode number 1 and 2 problems

---
 .gitignore            | 10 ++++++++
 1-two-sum.cpp         | 47 ++++++++++++++++++++++++++++++++++++
 2-add-two-numbers.cpp | 43 +++++++++++++++++++++++++++++++++
 main.cpp              | 56 +++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 156 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 1-two-sum.cpp
 create mode 100644 2-add-two-numbers.cpp
 create mode 100644 main.cpp

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..80c33d2
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,10 @@
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+*.dSYM
+
+main.dSYM/
+.*/
diff --git a/1-two-sum.cpp b/1-two-sum.cpp
new file mode 100644
index 0000000..35c625c
--- /dev/null
+++ b/1-two-sum.cpp
@@ -0,0 +1,47 @@
+#include <vector>
+#include <algorithm>
+
+struct Pair {
+    int first;
+    int second;
+
+    Pair(int f, int s) : first(f), second(s) {}
+    Pair() : first(0), second(0) {}
+    bool operator>(const Pair& other) const {
+        return first > other.first;
+    }
+    bool operator<(const Pair& other) const {
+        return first < other.first;
+    }
+};
+
+class TwoSumSolution {
+public:
+    std::vector<int> twoSum(std::vector<int>& nums, int target) {
+        std::vector<Pair> numPairs;
+        int i = 0;
+        for (auto num : nums) {
+            numPairs.emplace_back(num, i);
+            i++;
+        }
+        std::sort(numPairs.begin(), numPairs.end());
+        while (true)
+        {
+            int left = 0;
+            int right = static_cast<int>(numPairs.size()) - 1;
+            while (left < right) {
+                int sum = numPairs[left].first + numPairs[right].first;
+                if (sum == target) {
+                    return std::vector<int>{numPairs[left].second, numPairs[right].second};
+                } else if (sum < target) {
+                    left++;
+                } else {
+                    right--;
+                }
+            }
+            break;
+        }
+
+        return std::vector<int>{};
+    }
+};
diff --git a/2-add-two-numbers.cpp b/2-add-two-numbers.cpp
new file mode 100644
index 0000000..b977a3b
--- /dev/null
+++ b/2-add-two-numbers.cpp
@@ -0,0 +1,43 @@
+
+struct ListNode {
+      int val;
+      ListNode *next;
+      ListNode() : val(0), next(nullptr) {}
+      ListNode(int x) : val(x), next(nullptr) {}
+      ListNode(int x, ListNode *next) : val(x), next(next) {}
+  };
+
+class AddTwoNumbersSolution {
+public:
+    ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {
+        
+        if (!l1 && !l2) return nullptr;
+
+        ListNode* res = new ListNode(0);
+        ListNode* start = res;
+        ListNode* prev(nullptr);
+
+        int carry = 0;
+        while (l1 || l2) {
+            res->val += (l1? l1->val : 0);
+            res->val += (l2? l2->val : 0);
+            res->val += carry;
+            carry = res->val / 10;
+            if (carry) res->val -= 10;
+            
+            res->next = new ListNode(0);
+            prev = res;
+            res = res->next;
+            if (l1) l1 = l1->next;
+            if (l2) l2 = l2->next;
+        }
+        if ((carry == 0) && prev) {
+            delete prev->next;
+            prev->next = nullptr;
+        }
+        if (carry > 0) {
+            res->val++;
+        }
+        return start;
+    }
+};
diff --git a/main.cpp b/main.cpp
new file mode 100644
index 0000000..69204b0
--- /dev/null
+++ b/main.cpp
@@ -0,0 +1,56 @@
+#include <iostream>
+
+#include "1-two-sum.cpp"
+#include "2-add-two-numbers.cpp"
+
+int main() {
+    TwoSumSolution twoSumSolution;
+    auto v = std::vector<int>{11, 2, 8, 0, 35, 7, 15};
+    auto res = twoSumSolution.twoSum(v, 9);
+    std::cout << "Result: ";
+    for (auto index : res) {
+        std::cout << index << " ";
+    }
+    std::cout << std::endl;
+
+    AddTwoNumbersSolution addTwoNumbersSolution;
+    ListNode *l1 = new ListNode(2);
+    l1->next = new ListNode(4);
+    l1->next->next = new ListNode(3);
+    
+    ListNode *l2 = new ListNode(5);
+    l2->next = new ListNode(6);
+    l2->next->next = new ListNode(4);
+    auto resList = addTwoNumbersSolution.addTwoNumbers(l1, l2);
+    std::cout << "addTwoNumbers: ";
+    ListNode *listPtr = resList;
+    while (listPtr) {
+        std::cout << listPtr->val << " ";
+        listPtr = listPtr->next;
+    }
+    std::cout << std::endl;
+
+    ListNode *l3 = new ListNode(9);
+    l3->next = new ListNode(9);
+    l3->next->next = new ListNode(9);
+    l3->next->next->next = new ListNode(9);
+    l3->next->next->next->next = new ListNode(9);
+    l3->next->next->next->next->next = new ListNode(9);
+    l3->next->next->next->next->next->next = new ListNode(9);
+
+    ListNode *l4 = new ListNode(9);
+    l4->next = new ListNode(9);
+    l4->next->next = new ListNode(9);
+    l4->next->next->next = new ListNode(9);
+
+    resList = addTwoNumbersSolution.addTwoNumbers(l3, l4);
+    std::cout << "addTwoNumbers: ";
+    listPtr = resList;
+    while (listPtr) {
+        std::cout << listPtr->val << " ";
+        listPtr = listPtr->next;
+    }
+    std::cout << std::endl;
+
+    return 0;
+}