add steps recursive solution

Author: Connor Leech

udemy-interview-bootcamp-course/README.md

@@ -5,3 +5,13 @@ Udemy course link: [The Coding Interview Bootcamp: Algorithms + Data Structures]
 
 [Source code](https://github.com/StephenGrider/algocasts) for the lessons.
 
+## Additional Resources
+
+### Regular Expressions
+
+- An Introduction to Regular Expressions (Regex) In JavaScript ([Medium article](https://codeburst.io/an-introduction-to-regular-expressions-regex-in-javascript-1d3559e7ac9a))
+
+- Chapter 9: Regular Expressions ([Eloquent Javascript](https://eloquentjavascript.net/09_regexp.html))
+
+- Regular Expressions ([Javascript.info](https://javascript.info/regular-expressions))
+

udemy-interview-bootcamp-course/steps.js

@@ -20,19 +20,39 @@
 
 function steps(size){
 
-	for(let i = 0; i < size; i++){
-		let row = '';
+	for(let row = 0; row < size; row++){
+		let step = '';
 
-		for(let j = 0; j < size; j++){
-			if(i >= j){
-				row += '#';
+		for(let column = 0; column < size; column++){
+			if(row >= column){
+				step += '#';
 			} else {
-				row += ' ';
+				step += ' ';
 			}
 
 		}
-		console.log(row);
+		console.log(step);
 	}
 }
 
-steps(4);
+function stepsRecursive(size, row = 0, step = ''){
+	// base case
+	if(size === row){
+		return;
+	}
+
+	// move on to next row
+	if(size === step.length){
+		console.log(step);
+		return stepsRecursive(size, row + 1);
+	}
+
+	// build current row
+	step += (step.length <= row) ? '#' : ' ';
+
+	stepsRecursive(size, row, step);
+}
+
+stepsRecursive(4);
+
+