LJ Lesson 7 Pull Request: Populated file with working functions

lesson_07/conditionals/src/lesson7.ts

@@ -7,7 +7,11 @@ import { computeLexicographicDistance } from "./util.js";
  * @return True if the age corresponds to a voting age and false otherwise.
  */
 export function canVote(age: number): boolean {
-  return false;
+  if (age >= 18) {
+    return true;
+  } else {
+    return false;
+  }
 }
 
 /**
@@ -23,8 +27,13 @@ export function compareStrings(a: string, b: string): number {
   const distance = computeLexicographicDistance(a, b);
 
   // TODO(you): Finish this method.
-
-  return 0;
+  let distanceCompareNum = 0;
+  if (distance < 0) {
+    distanceCompareNum = -1;
+  } else if (distance > 0) {
+    distanceCompareNum = 1;
+  }
+  return distanceCompareNum;
 }
 
 /**
@@ -37,7 +46,31 @@ 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";
+  let letterGrade = "";
+  if (gpa >= 4.0) {
+    letterGrade = "A";
+  } else if (gpa < 4.0 && gpa >= 3.7) {
+    letterGrade = "A-";
+  } else if (gpa <= 3.69 && gpa >= 3.3) {
+    letterGrade = "B+";
+  } else if (gpa <= 3.29 && gpa >= 3.0) {
+    letterGrade = "B";
+  } else if (gpa <= 2.99 && gpa >= 2.7) {
+    letterGrade = "B-";
+  } else if (gpa <= 2.69 && gpa >= 2.3) {
+    letterGrade = "C+";
+  } else if (gpa <= 2.29 && gpa >= 2.0) {
+    letterGrade = "C";
+  } else if (gpa <= 1.99 && gpa >= 1.7) {
+    letterGrade = "C-";
+  } else if (gpa <= 1.69 && gpa >= 1.3) {
+    letterGrade = "D+";
+  } else if (gpa <= 1.29 && gpa >= 1.0) {
+    letterGrade = "D";
+  } else if (gpa <= 0.99) {
+    letterGrade = "F";
+  }
+  return letterGrade;
 }
 
 /**
@@ -47,7 +80,11 @@ export function convertGpaToLetterGrade(gpa: number): string {
  * @return The factorial of n.
  */
 export function computeFactorial(n: number): number {
-  return 0;
+  let product = 1;
+  for (let i = n; i >= 1; i--) {
+    product *= i;
+  }
+  return product;
 }
 
 /**
@@ -57,7 +94,11 @@ export function computeFactorial(n: number): number {
  * @return The sum of all the values.
  */
 export function addNumbers(values: number[]): number {
-  return 0;
+  let sum = 0;
+  for (const i of values) {
+    sum += i;
+  }
+  return sum;
 }
 
 /**
@@ -67,7 +108,19 @@ export function addNumbers(values: number[]): number {
  * @return An array containing the first `n` Fibonacci values.
  */
 export function getFirstNFibonacciNumbers(n: number): number[] {
-  return [];
+  const arr = [];
+  if (n >= 1) {
+    arr.push(1);
+  }
+  if (n >= 2) {
+    arr.push(1);
+  }
+  if (n >= 3) {
+    for (let i = 2; i < n; i++) {
+      arr.push(arr[i - 1] + arr[i - 2]);
+    }
+  }
+  return arr;
 }
 
 /**
@@ -98,5 +151,11 @@ export function binarySearch(
   // 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;
+  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);
+  }
 }