Two Sum — indices for target 8 #37 — DSA (Data Structures & Algorithms)

Problem

Given [1, 2, 3, 4, 5] and target 8, print the two indices (0-based) separated by space.

Hints

Store value → index in Dictionary

Your solution

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Solution

using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static void Main()
    {
        int[] nums = { 1, 2, 3, 4, 5 };
        int target = 8;
        var map = new Dictionary<int, int>();
        for (int j = 0; j < nums.Length; j++) {
            int need = target - nums[j];
            if (map.ContainsKey(need)) { Console.WriteLine(map[need] + " " + j); return; }
            map[nums[j]] = j;
        }
    }
}

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Explanation

Classic hash-map two sum — O(n) time.

Two Sum — indices for target 8 #37

Problem

Your solution

Solution

Explanation

Discussion