Week 2 js assignments

week-2/week-2-js/easy/anagram.js

@@ -5,7 +5,13 @@
 */
 
 function isAnagram(str1, str2) {
-
+if(str1.length !== str2.length){
+  return false;
+}
+function sortingStr(str){
+  return str.toLowerCase().split('').sort().join('');
+}
+return sortingStr(str1) === sortingStr(str2);
 }
 
 module.exports = isAnagram;

week-2/week-2-js/easy/expenditure-analysis.js

@@ -4,17 +4,31 @@
   transactions is an array where each
   Transaction - an object like 
         {
-		id: 1,
-		timestamp: 1656076800000,
-		price: 10,
-		category: 'Food',
-		itemName: 'Pizza',
-	}
+    id: 1,
+    timestamp: 1656076800000,
+    price: 10,
+    category: 'Food',
+    itemName: 'Pizza',
+  }
   Output - [{ category: 'Food', totalSpent: 10 }] // Can have multiple categories, only one example is mentioned here
 */
 
 function calculateTotalSpentByCategory(transactions) {
-  return [];
+  const totals = {};
+  for (let transaction of transactions) {
+    const { category, price } = transaction;
+    if (totals[category]) {
+      totals[category] += price;
+    }
+    else {
+      totals[category] = price;
+    }
+  }
+  const result = [];
+  for (let category in totals) {
+    result.push({ category, totalSpent: totals[category] });
+  }
+  return result;
 }
 
 module.exports = calculateTotalSpentByCategory;

week-2/week-2-js/easy/findLargestElement.js

@@ -1,12 +1,18 @@
 /*
-  Write a function `findLargestElement` that takes an array of numbers and returns the largest element.
-  Example:
-  - Input: [3, 7, 2, 9, 1]
-  - Output: 9
+  Write a function `findLargestElement` that takes an array of numbers and returns the largest element.
+  Example:
+  - Input: [3, 7, 2, 9, 1]
+  - Output: 9
 */
 
 function findLargestElement(numbers) {
-
+    let max = numbers[0];
+    for (let i = 0; i < numbers.length; i++) {
+        if (numbers[i] > max) {
+            max = numbers[i];
+        }
+    }
+    return max;
 }
 
 module.exports = findLargestElement;

week-2/week-2-js/hard/calculator.js

@@ -16,6 +16,50 @@
   Once you've implemented the logic, test your code by running
 */
 
-class Calculator {}
+class Calculator {
+  constructor() {
+    this.result = 0;
+  }
+  add(number) {
+    this.result += number;
+  }
+  subtract(number) {
+    this.result -= number;
+  }
+  multiply(number) {
+    this.result *= number;
+  }
+  divide(number) {
+    if (number == 0) {
+      throw new Error("Cannot divide by zero");
+    }
+    this.result /= number;
+  }
+  clear() {
+    this.result = 0;
+  }
+  getResult() {
+    return this.result;
+  }
+
+  calculate(inputExpression) {
+    const cleanedExpression = inputExpression.split(' ').join('');
+    const allowed = '0123456789+-*/().';
+    for (let ch of cleanedExpression) {
+      if (!allowed.includes(ch)) {
+        throw new Error("Invalid Expression");
+      }
+    }
+    try {
+      this.result = eval(inputExpression);
+    } catch (error) {
+      throw new Error("Invalid expression");
+    }
+    if (this.result === Infinity) {
+      throw new Error("Cannot divide by zero");
+    }
+    return this.result;
+  }
+}
 
 module.exports = Calculator;

week-2/week-2-js/hard/todo-list.js

@@ -11,7 +11,34 @@
 */
 
 class Todo {
-
+  constructor() {
+    this.todos = [];
+  }
+  add(todo) {
+    this.todos.push(todo);
+  }
+  remove(indexOfTodo) {
+    if (indexOfTodo >= 0 && indexOfTodo < this.todos.length) {
+      this.todos.splice(indexOfTodo, 1);
+    }
+  }
+  update(index, updatedTodo) {
+    if (index >= 0 && index < this.todos.length) {
+      this.todos[index] = updatedTodo;
+    }
+  }
+  getAll() {
+    return this.todos;
+  }
+  get(indexOfTodo) {
+    if (indexOfTodo >= 0 && indexOfTodo < this.todos.length) {
+      return this.todos[indexOfTodo];
+    }
+    return null;
+  }
+  clear() {
+    this.todos = [];
+  }
 }
 
 module.exports = Todo;

week-2/week-2-js/medium/countVowels.js

@@ -6,7 +6,15 @@
 */
 
 function countVowels(str) {
-    // Your code here
+  // Your code here
+  let count = 0;
+  const vowels = 'aeiouAEIOU';
+  for (let s of str) {
+    if (vowels.includes(s)) {
+      count++;
+    }
+  }
+  return count;
 }
 
 module.exports = countVowels;

week-2/week-2-js/medium/palindrome.js

@@ -4,6 +4,23 @@
 */
 
 function isPalindrome(str) {
+  let lowerStr = '';
+  for (let ch of str) {
+    if ((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')) {
+      lowerStr += ch.toLowerCase();
+    } else if (ch >= '0' && ch <= '9') {
+      lowerStr += ch;
+    }
+  }
+  let left = 0;
+  let right = lowerStr.length - 1;
+  while (left < right) {
+    if (lowerStr[left] !== lowerStr[right]) {
+      return false;
+    }
+    left++;
+    right--;
+  }
   return true;
 }
 

week-2/week-2-js/medium/times.js

@@ -9,5 +9,15 @@ There is no automated test for this one, this is more for you to understand time
 */
 
 function calculateTime(n) {
-    return 0.01;
-}
+    const startTime = performance.now();
+    let sum = 0;
+    for(let i = 1;i<=n ;i++){
+        sum+= i;
+    }
+    const endTime = performance.now();
+    return (endTime-startTime)/1000;
+}
+
+console.log('Time for sum from 1 to 100:', calculateTime(100));
+console.log('Time for sum from 1 to 100000:', calculateTime(100000));
+console.log('Time for sum from 1 to 1000000000:', calculateTime(1000000000));