# Data Structures & Algorithms using Rust: Two Sum

Sivakumar Updated on ・1 min read

As part of Data Structures and Algorithms implementation using Rust, today we will explore `Two Sum` problem.

###### Problem Statement
``````Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.

You may assume that each input would have exactly one solution, and you may not use the same element twice.

You can return the answer in any order.
``````
###### Instructions
``````Example 1:

Input: nums = [2,7,11,15], target = 9
Output: [0,1]
Output: Because nums[0] + nums[1] == 9, we return [0, 1].
Example 2:

Input: nums = [3,2,4], target = 6
Output: [1,2]
Example 3:

Input: nums = [3,3], target = 6
Output: [0,1]

Constraints:

2 <= nums.length <= 105
-109 <= nums[i] <= 109
-109 <= target <= 109
``````
###### Solution

Please find below the solution implemented using Rust

``````use std::collections::HashMap;

impl Solution {
pub fn two_sum(nums: Vec<i32>, target: i32) -> Vec<i32> {
let l = nums.len();
let mut m = HashMap::new();
for i in 0..l {
let t = target-nums[i];
if let Some(x) = m.get(&t) {
return vec![*x, i as i32];
} else {
m.insert(nums[i], i as i32);
}
}
vec![]
}
}
``````
###### Outcome from Leetcode

Runtime: 0 ms, faster than 100.00% of Rust online submissions for Two Sum.
Memory Usage: 2.5 MB, less than 23.25% of Rust online submissions for Two Sum.