Initial commit

.gitignore

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+# ---> C++
+# Prerequisites
+*.d
+
+# Compiled Object files
+*.slo
+*.lo
+*.o
+*.obj
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Compiled Dynamic libraries
+*.so
+*.dylib
+*.dll
+
+# Fortran module files
+*.mod
+*.smod
+
+# Compiled Static libraries
+*.lai
+*.la
+*.a
+*.lib
+
+# Executables
+*.exe
+*.out
+*.app
+

README.md

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+# LeetCode-1.Two_Sum_via_CPP
+
+## Problem Statement - Two Sum
+Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.
+You may assume that each input would have exactly one solution, and you may not use the same element twice.
+You can return the answer in any order.
+
+## Example 1:
+Input: nums = [2,7,11,15], target = 9
+
+Output: [0,1]
+
+Explanation: Because nums[0] + nums[1] == 9, we return [0, 1].
+
+## Example 2:
+Input: nums = [3,2,4], target = 6
+
+Output: [1,2]
+
+## Example 3:
+Input: nums = [3,3], target = 6
+
+Output: [0,1]
+
+## Constraints:
+2 <= nums.length <= 104
+
+-109 <= nums[i] <= 109
+
+-109 <= target <= 109
+
+Only one valid answer exists.

main.cpp

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+#include <vector>
+#include <unordered_map>
+
+class Solution {
+public:
+    std::vector<int> twoSum(std::vector<int>& nums, int target) {
+        std::unordered_map<int, int> num_map; // Stores number and its index
+        for (int i = 0; i < nums.size(); ++i) {
+            int complement = target - nums[i];
+            if (num_map.find(complement) != num_map.end()) {
+                return {num_map[complement], i}; // Found the two indices
+            }
+            num_map[nums[i]] = i; // Store index of the current number
+        }
+        return {};
+    }
+};