Added thomas algo in js

Author: Ariana1729

contents/thomas_algorithm/code/javascript/thomas.js

@@ -0,0 +1,26 @@
+function thomas(a, b, c, d) {
+	const size = a.length;
+
+	c[0] /= b[0];
+	d[0] /= b[0];
+
+	for(let i = 1; i < size; ++i ) {
+		let scale = 1 / (b[i] - c[i-1] * a[i]);
+		c[i] *= scale;
+		d[i] = (d[i] - a[i] * d[i-1]) * scale;
+	}
+
+	for(let i = size-2; i>=0; --i) {
+		d[i] -= c[i] * d[i+1];
+	}
+
+	return d;
+}
+
+a = [0, 2, 3];
+b = [1, 3, 6];
+c = [4, 5, 0];
+d = [7, 5, 3];
+
+sol = thomas(a,b,c,d);
+console.log(sol);

contents/thomas_algorithm/thomas_algorithm.md

@@ -1,4 +1,4 @@
-# Thomas Algorithm
+s# Thomas Algorithm
 
 As alluded to in the [Gaussian Elimination chapter](../gaussian_elimination/gaussian_elimination.md), the Thomas Algorithm (or TDMA, Tri-Diagonal Matrix Algorithm) allows for programmers to **massively** cut the computational cost of their code from $$ O(n^3)$$ to $$O(n)$$ in certain cases!
 This is done by exploiting a particular case of Gaussian Elimination where the matrix looks like this:
@@ -111,8 +111,6 @@ You will find this algorithm implemented [in this project](https://scratch.mit.e
 [import, lang:"java"](code/java/thomas.java)
 {% sample lang="hs" %}
 [import, lang:"haskell"](code/haskell/thomas.hs)
-{% sample lang="go" %}
-[import, lang:"go"](code/golang/thomas.go)
 {% sample lang="swift" %}
 [import, lang:"swift"](code/swift/thomas.swift)
 {% sample lang="php" %}
@@ -121,6 +119,8 @@ You will find this algorithm implemented [in this project](https://scratch.mit.e
 [import, lang:"nim"](code/nim/thomas_algorithm.nim)
 {% sample lang="cpp" %}
 [import, lang:"c_cpp"](code/c++/thomas.cpp)
+{% sample lang="js" %}
+[import, lang:"js"](code/javascript/thomas.js)
 {% endmethod %}
 
 <script>