feat: adds missing functions on lesson7 and part_d

Author: Ezra Nyabuti

lesson_07/conditionals/.env.test

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

lesson_07/conditionals/src/lesson7.ts

@@ -11,6 +11,15 @@ export function compareStrings(a: string, b: string): number {
   // The distance will be a number less than 0 if string `a` is lexicographically less than `b`, 1
   // if it is greater, and 0 if the strings are equal.
   const distance = computeLexicographicDistance(a, b);
+  {
+    if (distance < 0) {
+      return -1;
+    } else if (distance > 0) {
+      return 1;
+    } else {
+      return 0;
+    }
+  }
 
   // TODO(you): Finish this method.
 
@@ -24,7 +33,15 @@ export function compareStrings(a: string, b: string): number {
  * @return The factorial of n.
  */
 export function computeFactorial(n: number): number {
-  return 0;
+  if (n === 0) {
+    return 1;
+  } else if (n < 0) {
+    return 0;
+  } else if (n === 1) {
+    return 1;
+  } else {
+    return n * computeFactorial(n - 1);
+  }
 }
 
 /**
@@ -34,7 +51,15 @@ export function computeFactorial(n: number): number {
  * @return An array containing the first `n` Fibonacci values.
  */
 export function getFirstNFibonacciNumbers(n: number): number[] {
-  return [];
+  if (n <= 0) return [];
+  if (n === 1) return [1];
+  if (n === 2) return [1, 1];
+
+  const fibonacciNumbers = [1, 1];
+  for (let i = 2; i < n; i++) {
+    fibonacciNumbers.push(fibonacciNumbers[i - 1] + fibonacciNumbers[i - 2]);
+  }
+  return fibonacciNumbers;
 }
 
 /**
@@ -60,7 +85,13 @@ export function binarySearch(
   const pivotIndex = Math.floor((start + end) / 2); // The index in the middle of the array.
 
   // TODO(you): Finish implementing this algorithm
-
+  if (values[pivotIndex] === value) {
+    return pivotIndex;
+  } else if (values[pivotIndex] > value) {
+    return binarySearch(values, start, pivotIndex - 1, value);
+  } else {
+    return binarySearch(values, pivotIndex + 1, end, value);
+  }
   // If values[pivotIndex] is equal to value then return `pivotIndex`.
   // Else if values[pivotIndex] is greater than the value, then
   // call `binarySearch(values, start, pivotIndex - 1, value)` and return its value;

lesson_07/conditionals/src/part_d.ts

@@ -7,6 +7,9 @@
  * @returns
  */
 export function isWithinRange(num: number, min: number, max: number): boolean {
+  if (num >= min && num <= max) {
+    return true;
+  }
   return false;
 }
 
@@ -19,7 +22,12 @@ export function isWithinRange(num: number, min: number, max: number): boolean {
  * @returns
  */
 export function isValidTriangle(a: number, b: number, c: number): boolean {
-  return false;
+  switch (true) {
+    case a + b > c && a + c > b && b + c > a:
+      return true;
+    default:
+      return false;
+  }
 }
 
 /**
@@ -30,5 +38,17 @@ export function isValidTriangle(a: number, b: number, c: number): boolean {
  * @returns
  */
 export function getSeason(month: number): string {
+  if (isWithinRange(month, 1, 12)) {
+    switch (true) {
+      case isWithinRange(month, 3, 5):
+        return "Spring";
+      case isWithinRange(month, 6, 8):
+        return "Summer";
+      case isWithinRange(month, 9, 11):
+        return "Fall";
+      default:
+        return "Winter";
+    }
+  }
   return "Invalid month";
 }