feat: adds Tyran's Lesson 06 expression_calculator/stretch functions

lesson_06/expression/.env.test

@@ -1 +1 @@
-HW_VERSION=your assigned version here
+HW_VERSION=D

lesson_06/expression/src/expression_calculator.ts

@@ -2,7 +2,28 @@ export class ExpressionCalculator {
   /** Returns a calculation involving a, b, c, d, and e */
   calculate(a: number, b: number, c: number, d: number, e: number): number {
     // Implement your code here to return the correct value.
-    return 0;
+    // Function to implement: a * b / MAtjh.pow(c + d, e)
+
+    const answer = this.divide(
+      this.multiply(a, b),
+      this.pow(this.add(c, d), e),
+    );
+    return answer;
+  }
+
+  add(a: number, b: number): number {
+    return a + b;
+  }
+
+  multiply(a: number, b: number): number {
+    return a * b;
+  }
+
+  divide(a: number, b: number): number {
+    if (b === 0) {
+      throw new Error("Division by zero is not allowed.");
+    }
+    return a / b;
   }
 
   pow(base: number, exponent: number): number {

lesson_06/tyranricejr/README.md

@@ -0,0 +1,75 @@
+# isValidAlphaAbbreviation Functionality in TypeScript
+
+This markdown file documents the implementation of a function that validates whether an abbreviation is a correct ***alpha abbreviation*** of a given word. It includes code snippets, test cases to verify correctness, and an explanation of the logic used. The document also highlights key considerations when working with TypeScript vs. plain JavaScript.
+
+## isValidAlphaAbbreviation.ts
+
+### Params:
+- word: string → the original word to validate against.
+- abbr: string → the abbreviation sequence to check.
+
+### Return:
+- boolean → true if the abbreviation correctly represents the word, false otherwise.
+
+```typescript
+function isValidAlphaAbbreviation(word: string, abbr: string): boolean {
+    if(word == "" || abbr == "") return false;
+    if(word.length < abbr.length) return false;
+
+    // Letters mapped to numeric skip values (a=1, ..., z=26)
+    const AlphaToNumberValues = {
+        "a": 1, "b": 2, "c": 3, "d": 4, "e": 5, "f": 6, "g": 7, "h": 8, "i": 9,
+        "j": 10, "k": 11, "l": 12, "m": 13, "n": 14, "o": 15, "p": 16, "q": 17,
+        "r": 18, "s": 19, "t": 20, "u": 21, "v": 22, "w": 23, "x": 24,
+        "y": 25, "z": 26    
+    };
+
+    let wordIndex = 0;
+    let isAbbreviation = true;
+    for (let abbrIndex = 0; abbrIndex < abbr.length; abbrIndex++) {
+        // Even indices: literal character match
+        if(abbrIndex % 2 == 0) {
+            if(abbr[abbrIndex] != word[wordIndex]) {
+                isAbbreviation = false;
+                break;
+            }
+            else {
+                wordIndex++;
+            }
+        }
+        // Odd indices: skip value
+        else if(abbrIndex % 2 == 1) {
+            wordIndex += AlphaToNumberValues[abbr[abbrIndex]];
+        }
+    }
+
+    return isAbbreviation && wordIndex === word.length;
+}
+```
+
+### Example Test Cases:
+```typescript
+    console.log("\n--- Test Case 1 ---")
+    console.log("isValidAlphaAbbreviation(word: internationalization, abbr: imzdn) Should Return True")
+    console.log("Result: ", isValidAlphaAbbreviation("internationalization", "imzdn"))
+
+    console.log("\n--- Test Case 2 ---")
+    console.log("isValidAlphaAbbreviation(word: internationalization, abbr: imz) Should Return False")
+    console.log("Result: ", isValidAlphaAbbreviation("internationalization", "imz"))
+
+    console.log("\n--- Test Case 3 ---")
+    console.log("isValidAlphaAbbreviation(word: substitution, abbr: sjn) Should Return True")
+    console.log("Result: ", isValidAlphaAbbreviation("substitution", "sjn"))
+
+    console.log("\n--- Test Case 4 ---")
+    console.log("isValidAlphaAbbreviation(word: substitution, abbr: san) Should Return False")
+    console.log("Result: ", isValidAlphaAbbreviation("substitution", "san"))
+
+    console.log("\n--- Test Case 5 ---")
+    console.log("isValidAlphaAbbreviation(word: test, abbr: ab) Should Return False")
+    console.log("Result: ", isValidAlphaAbbreviation("test", "ab")) 
+
+    console.log("\n--- Test Case 6 ---")
+    console.log("isValidAlphaAbbreviation(word: test, abbr: tbt) Should Return True")
+    console.log("Result: ", isValidAlphaAbbreviation("test", "tbt")) 
+```