fix: completed the functions

Author: Cogbonnia

lesson_07/conditionals/src/lesson7.ts

@@ -7,6 +7,9 @@ import { computeLexicographicDistance } from "./util.js";
  * @return True if the age corresponds to a voting age and false otherwise.
  */
 export function canVote(age: number): boolean {
+  if (age >= 18) {
+    return true;
+  }
   return false;
 }
 
@@ -22,9 +25,14 @@ export function compareStrings(a: string, b: string): number {
   // 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.
-
-  return 0;
 }
 
 /**
@@ -37,7 +45,29 @@ export function compareStrings(a: string, b: string): number {
  * @return The letter grade ("A+", "A", "A-", "B+", etc.).
  */
 export function convertGpaToLetterGrade(gpa: number): string {
-  return "F";
+  if (gpa == 4.0) {
+    return "A";
+  } else if (gpa <= 3.99 && gpa >= 3.7) {
+    return "A-";
+  } else if (gpa <= 3.69 && gpa >= 3.3) {
+    return "B+";
+  } else if (gpa <= 3.29 && gpa >= 3.0) {
+    return "B";
+  } else if (gpa <= 2.99 && gpa >= 2.7) {
+    return "B-";
+  } else if (gpa <= 2.69 && gpa >= 2.3) {
+    return "C+";
+  } else if (gpa <= 2.29 && gpa >= 2.0) {
+    return "C";
+  } else if (gpa <= 1.99 && gpa >= 1.7) {
+    return "C-";
+  } else if (gpa <= 1.69 && gpa >= 1.3) {
+    return "D+";
+  } else if (gpa <= 1.29 && gpa >= 1.0) {
+    return "D";
+  } else {
+    return "F";
+  }
 }
 
 /**
@@ -47,17 +77,26 @@ export function convertGpaToLetterGrade(gpa: number): string {
  * @return The factorial of n.
  */
 export function computeFactorial(n: number): number {
-  return 0;
+  if (n == 0 || n == 1) {
+    return 1;
+  } else if (n > 1) {
+    return n * computeFactorial(n - 1);
+  }
+  return n;
 }
-
+/* 4! = 4 x 3 x 2 x 1 = 24*/
 /**
  * Adds all of the provided values and returns the sum.
  *
  * @param values The values to sum.
  * @return The sum of all the values.
  */
 export function addNumbers(values: number[]): number {
-  return 0;
+  let sum = 0;
+  for (const value of values) {
+    sum += value;
+  }
+  return sum;
 }
 
 /**
@@ -67,7 +106,17 @@ export function addNumbers(values: number[]): number {
  * @return An array containing the first `n` Fibonacci values.
  */
 export function getFirstNFibonacciNumbers(n: number): number[] {
-  return [];
+  const fibArray: number[] = [];
+  let a = 0;
+  let b = 1;
+  let c: number;
+  while (fibArray.length < n) {
+    c = a;
+    a = b;
+    b = c + b;
+    fibArray.push(a);
+  }
+  return fibArray;
 }
 
 /**
@@ -94,9 +143,15 @@ export function binarySearch(
 
   // 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;
   // Else call `binarySearch(values, pivotIndex + 1, end, value)` and return its value.
-  return -1;
 }