# Blogs Hub

### by Sumit Chourasia | Apr 18, 2020 | Category :coding | Tags : आसानleetcodeडेटा-संरचनाalgorithm

#### Two sum problem ( Without Repeating Numbers ) - मिनी टीवी

Given an array of integers, return 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:

``````using System;
using System.Collections.Generic;
using System.Text;

namespace LeetCode.Easy
{
class TwoSumSolution
{
public int[] TwoSum(int[] nums, int target)
{
var dict = new Dictionary<int, int>();
var sumSetIndex = new int[2];
for (int i=0;i<nums.Length;i++)
{
dict.Add(nums[i], i);
}

foreach (var num in nums)
{
if (dict.ContainsKey(num))
{
if(dict.ContainsKey(target - num))
{
sumSetIndex[0] = dict[num];
sumSetIndex[1] = dict[target - num];
}
}
}

return sumSetIndex;
}
}
}``````

Time Complexity: O(n) - For a complete Iteration of N Numbers.

Space Complexity: O(n) - For HashMap

Contributed By: Sumit Chourasia
Contributed By: Sumit Chourasia
Contributed By: Sumit Chourasia
Contributed By: Sumit Chourasia