chore(Rust): add merge sort (#403)

* Add merge sort algorithm

* add rust files to gitignore

* Revert "add rust files to gitignore"

This reverts commit d6a1ab819b.

* Move gitignore to cargo project

* create readme for merge sort

* add merge sort

algorithms/Rust/README.md

@@ -1,4 +1,5 @@
 
 # Rust
 
-1. [Palindrome Check](strings/palindrome/README.md)
+1. [Palindrome Check](strings/palindrome/README.md)
+2. [Merge Sort](sorting/merge-sort/README.md)

algorithms/Rust/sorting/merge-sort/.gitignore

@@ -0,0 +1,4 @@
+### Rust
+Cargo.lock
+# Rust compiled output
+target

algorithms/Rust/sorting/merge-sort/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "merge-sort"
+version = "0.1.0"
+authors = ["Akshat Adsule <30205531+AkshatAdsule@users.noreply.github.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+rand = "0.8.3"

algorithms/Rust/sorting/merge-sort/README.md

@@ -0,0 +1,15 @@
+This sorts an array using Merge Sort. The sort is generic and will work with with any `Vec` whose items have the `std::cmp::Ord ` and `Copy` traits. More information about Merge Sort can be found [here](https://en.wikipedia.org/wiki/Merge_sort)
+
+## Prerequisites
+
+- Rust (https://rust-lang.org)
+
+## Instructions for running the project
+
+- Open a terminal/powershell window in the folder/directory.
+
+- Run the following command
+
+  ```bash
+  cargo run --release
+  ```

algorithms/Rust/sorting/merge-sort/src/main.rs

@@ -0,0 +1,66 @@
+use rand::{distributions::Uniform, Rng};
+
+fn main() {
+    // Create random numbers
+    let range = Uniform::from(0..=100);
+    let values: Vec<i32> = rand::thread_rng().sample_iter(&range).take(100).collect();
+    println!("Sorting: {:?}",values);
+    let result = merge_sort(values);
+    println!("Sorted:  {:?}", result);
+}
+
+// Limit type to only objects that can be ordered, cloned and copied
+fn merge_sort<T: std::cmp::Ord + Copy>(nums: Vec<T>) -> Vec<T> {
+    // If array only has one item, it is already sorted :-)
+    if nums.len() == 1 {
+        return vec![nums[0]];
+    }
+
+    // If array has 2 items, just compare the values and sort
+    if nums.len() == 2 {
+        if nums[0] <= nums[1] {
+            return vec![nums[0], nums[1]];
+        } else {
+            return vec![nums[1], nums[0]];
+        }
+    }
+
+    // Split into 2
+    let half = nums.len() / 2;
+    let mut left = merge_sort((&nums[0..half]).to_vec());
+    let mut right = merge_sort((&nums[half..]).to_vec());
+
+    let mut sorted: Vec<T> = Vec::new();
+
+    loop {
+        // If either array is empty, the values in the other array must be larger
+        // and so we should dump the remaining array's content into the sorted array
+        if left.is_empty() {
+            for i in right {
+                sorted.push(i);
+            }
+            break;
+        }
+        if right.is_empty() {
+            for i in left {
+                sorted.push(i);
+            }
+            break;
+        }
+
+        // Merge arrays
+        if left[0] >= right[0] {
+            sorted.push(right[0]);
+            right.remove(0);
+            continue;
+        }
+        if left[0] <= right[0] {
+            sorted.push(left[0]);
+            left.remove(0);
+            continue;
+        }
+    }
+
+    // return sorted array
+    sorted
+}