C++20 Ranges: Two Sum Algorithm for Finding Target Sum in an Array

#include #include <unordered_map>

class Solution { public: std::vector twoSum(std::vector& nums, int target) { std::unordered_map<int, int> map; for (auto [i, num] : nums | std::ranges::views::enumerate) { auto it = map.find(target - num); if (it != map.end()) { return {it->second, i}; } map[num] = i; } return {}; } };