Two Sum

Problem

Given an array of integers, return the indices of the two numbers such that they add up to a specific target.
You may assume that each input would have exactly one solution, and you may not use the same element twice.
Example:
Given nums = [2, 7, 11, 15], target = 9,
Because nums[0] + nums[1] = 2 + 7 = 9,
return [0, 1].

Solution

This solution is in C++. Our A.I. can create solutions in multiple languages.

kayakane

#include <iostream>
#include <vector>
#include <unordered_map>

using namespace std;

vector<int> twoSum(vector<int>& nums, int target) {
    unordered_map<int, int> map;
    vector<int> result;
    for (int i = 0; i < nums.size(); i++) {
        if (map.find(target - nums[i]) != map.end()) {
            result.push_back(map[target - nums[i]]);
            result.push_back(i);
            return result;
        }
        map[nums[i]] = i;
    }
    return result;
}

int main() {
    vector<int> nums = {2, 7, 11, 15};
    int target = 9;
    vector<int> result = twoSum(nums, target);
    for (int i = 0; i < result.size(); i++) {
        cout << result[i] << " ";
    }
    cout << end l;
    return 0;
}