leetcode two sum problem solution with c++

 #include <vector>

#include <unordered_map>

#include <iostream>

std::vector<int> twoSum(std::vector<int>& nums, int target) {

    std::unordered_map<int, int> numMap; // Map to store number and its index

    for (int i = 0; i < nums.size(); ++i) {

        int complement = target - nums[i];

        if (numMap.find(complement) != numMap.end()) {

            return {numMap[complement], i};

        }

        numMap[nums[i]] = i;

    }

    return {}; // Return an empty vector if no solution found, though per problem statement there is always one solution

}

int main() {

    // Example 1

    std::vector<int> nums1 = {2, 7, 11, 15};

    int target1 = 9;

    std::vector<int> result1 = twoSum(nums1, target1);

    std::cout << "[" << result1[0] << "," << result1[1] << "]" << std::endl;

    // Example 2

    std::vector<int> nums2 = {3, 2, 4};

    int target2 = 6;

    std::vector<int> result2 = twoSum(nums2, target2);

    std::cout << "[" << result2[0] << "," << result2[1] << "]" << std::endl;

    // Example 3

    std::vector<int> nums3 = {3, 3};

    int target3 = 6;

    std::vector<int> result3 = twoSum(nums3, target3);

    std::cout << "[" << result3[0] << "," << result3[1] << "]" << std::endl;

    return 0;

}