Editing lesson7.ts with finished functions

Author: jjcapparell

lesson_07/conditionals/src/lesson7.ts

@@ -7,7 +7,12 @@ 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;
+  }
 }
 
 /**
@@ -21,23 +26,86 @@ 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);
-
-  // TODO(you): Finish this method.
-
-  return 0;
+  if (distance>0){
+    return 1;
+  }
+  if (distance<0){
+    return -1
+  }
+  else{
+    return 0;
+  }
 }
 
 /**
  * Converts a GPA on the 4.0 scale to the corresponding letter grade using the college board
  * scale. See
  * https://bigfuture.collegeboard.org/plan-for-college/college-basics/how-to-convert-gpa-4.0-scale
  * for details.
- *
+ *  A+	97-100	4.0
+    A	93-96	4.0
+    A-	90-92	3.7
+    B+	87-89	3.3
+    B	83-86	3.0
+    B-	80-82	2.7
+    C+	77-79	2.3
+    C	73-76	2.0
+    C-	70-72	1.7
+    D+	67-69	1.3
+    D	65-66	1.0
+    E/F	Below 65	0.0
  * @param gpa The GPA value.
  * @return The letter grade ("A+", "A", "A-", "B+", etc.).
  */
 export function convertGpaToLetterGrade(gpa: number): string {
-  return "F";
+  let letterGrade = "N/A";
+  if (gpa===4.0){
+    letterGrade = "A";
+    return letterGrade;
+  }
+  else if (gpa>=3.7 && gpa<4.0){
+    letterGrade = "A-";
+    return letterGrade;
+  }
+  else if (gpa>=3.3 && gpa<3.7){
+    letterGrade = "B+";
+    return letterGrade;
+  }
+  else if (gpa>=3.0 && gpa<3.3){
+    letterGrade = "B";
+    return letterGrade;
+  }
+  else if (gpa>=2.7 && gpa<3.0){
+    letterGrade = "B-";
+    return letterGrade;
+  }
+  else if (gpa>=2.3 && gpa<2.7){
+    letterGrade = "C+";
+    return letterGrade;
+  }
+  else if (gpa>=2.0 && gpa<2.3){
+    letterGrade = "C";
+    return letterGrade;
+  }
+  else if (gpa>=1.7 && gpa<2.0){
+    letterGrade = "C-";
+    return letterGrade;
+  }
+  else if (gpa>=1.3 && gpa<1.7){
+    letterGrade = "D+";
+    return letterGrade;
+  }
+  else if (gpa>=1.0 && gpa<1.3){
+    letterGrade = "D";
+    return letterGrade;
+  }
+  else if (gpa>=0 && gpa<1.0){
+    letterGrade = "F";
+    return letterGrade;
+  }
+  else{
+    return letterGrade;
+  }
 }
 
 /**
@@ -47,7 +115,15 @@ export function convertGpaToLetterGrade(gpa: number): string {
  * @return The factorial of n.
  */
 export function computeFactorial(n: number): number {
-  return 0;
+  let fact = 0
+  if (n>0){
+    fact = 1
+    for (let i=n; i>=0; i--){
+      fact *= i;
+    }
+    return fact;
+  }
+  return fact;
 }
 
 /**
@@ -57,7 +133,14 @@ export function computeFactorial(n: number): number {
  * @return The sum of all the values.
  */
 export function addNumbers(values: number[]): number {
-  return 0;
+  let sum=0;
+  if (values.length>0){
+    for (let i = 0; i<values.length; i++){
+      sum+=values[i];
+    }
+    return sum;
+  }
+  return sum;
 }
 
 /**
@@ -67,7 +150,19 @@ export function addNumbers(values: number[]): number {
  * @return An array containing the first `n` Fibonacci values.
  */
 export function getFirstNFibonacciNumbers(n: number): number[] {
-  return [];
+  let list: number[] = [];
+  if (n>=1){
+    list.push(0);
+  }
+  if (n>=2){
+    list.push(1);
+  }
+  if (n>=3){
+    for (let i=2; i<=n; i++){
+      list[i] = list[i-1] + list[i-2];
+    }
+  }
+  return list;
 }
 
 /**
@@ -98,5 +193,13 @@ 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);
+  }
 }