Added accepted solutions for leetcode number 1 and 2 problems

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>{};
+    }
+};