Two_Sum_Problem.cpp

#include <iostream>
#include <vector>
#include <unordered_map>
using namespace std;

class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
        vector<int> ans;
        unordered_map<int, int> mp;
        for(int i = 0; i < nums.size(); i++) {
            if(mp.find(target - nums[i]) != mp.end()) {
                ans.push_back(mp[target - nums[i]]);
                ans.push_back(i);
                return ans;
            }
            mp[nums[i]] = i;
        }
        return ans;
    }
};

// Driver code
int main() {
    Solution sol;
    vector<int> nums = {2, 7, 11, 15};
    int target = 9;

    vector<int> result = sol.twoSum(nums, target);

    if(result.size() == 2) {
        cout << "Indices: " << result[0] << " and " << result[1] << endl;
    } else {
        cout << "No two numbers found that sum to the target." << endl;
    }

    return 0;
}