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Suppose we have one equation in this form: a + b = c, now any one of the terms of a, b or c is missing. We have to find the missing one.So, if the input is like ? + 4 = 9, then the output will be 5To solve this, we will follow these steps −delete all blank spaces from the string and change (+ and = to comma ', ')elements := a list of elements by splitting the string separated by commaidx := 0for i in range 0 to size of elements, doif elements[i] is not numeric, thenidx ... Read More
Suppose there are n number of cashiers exchanging the money, at the moment, the i-th cashier had ki number of people in front of him/her. Now, the j-th person in the line to i-th cashier had m[i, j] notes. We have to find how early can one exchange his/her notes. We have to keep in mind that the cashier spent 5 seconds to scan a single note.After completing scanning of every note for the customer, he/she took 15 seconds to exchange the notes.So, if the input is like Input : n = 6, k = [12, 12, 12, 12, 12, ... Read More
Let’s say, we have an array of objects like this −const arr = [ { id: 1, parent_id: 0, title: 'Movies' }, { id: 2, parent_id: 0, title: 'Music' }, { id: 3, parent_id: 1, title: 'Russian movies' }, { id: 4, parent_id: 2, title: 'Russian music' }, { id: 5, parent_id: 3, title: 'New' }, { id: 6, parent_id: 3, title: 'Top10' }, { id: 7, parent_id: 4, title: 'New' }, { id: 8, parent_id: 4, title: 'Top10' }, { id: 9, parent_id: 0, title: 'Soft' } ];We are required ... Read More
We have an array of strings each of which contain one or more numbers like this −const arr = ['di5aster', 'ca1amity', 'cod3', 'ho2me3', 'ca11ing'];We are required to write a sorting function that sorts this array in ascending order of the numbers present in the strings. The correct order will be −const output = [ 'ca1amity', 'cod3', 'di5aster', 'ca11ing', 'ho2me3' ];Therefore, let’s write the code for this problem −Exampleconst arr = ['di5aster', 'ca1amity', 'cod3', 'ho2me3', 'ca11ing']; const filterNumber = str => { return +str .split("") .filter(el => el.charCodeAt() >= 48 && el.charCodeAt() { return filterNumber(a) - ... Read More
Let’s say, we are required to write a function that takes in an array of Numbers and number n, where n >= any number of the array. The function is required to break the array into subarrays if the sum of consecutive elements of the array exceeds the number n.For example −// if the original array is: const arr = [2, 1, 2, 1, 1, 1, 1, 1]; // and the number n is 4 // then the output array should be: const output = [ [ 2, 1 ], [ 2, 1, 1 ], [ 1, 1, 1 ] ... Read More
We have to write a function that takes in an array, removes all duplicates from it and inserts the same number of empty strings at the end.For example − If we find 4 duplicate values we have to remove then all and insert four empty strings at the end.Therefore, let’s write the code for this problem −Exampleconst arr = [1, 2, 3, 1, 2, 3, 2, 2, 3, 4, 5, 5, 12, 1, 23, 4, 1]; const deleteAndInsert = arr => { const creds = arr.reduce((acc, val, ind, array) => { let { count, res } ... Read More
We have to write a simple function in JavaScript that takes in an array of Numbers (nested to any level) and return the greatest number present in the array.For example − If the input array is −const arr = [ 34, 65, 67, [ 43, 76, 87, 23, 56, 7, [ 54, 7, 87, 23, 79, 314, 2 ], 54 ], 54, 4, 2 ];Then the output should be −314We will use recursion to find the greatest number in the array. ... Read More
Suppose we have two arrays, for an example consider the following two −const array1 = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h']; const array2 = [ 1, 0, 0, 1 , 0, 0, 1, 0];Both the arrays are bound to have the same length. We are required to write a function that when provided with an element from the second array, returns a subarray from the first array of the all elements whose index corresponds to the index of the element we took as an argument in the second array.For example: findSubArray(0) should return −[‘b’, ‘c’, ‘e’, ‘f’, ‘h’]Because ... Read More
Let’s say, we have an array of objects like this −const arr = [ {"id":0, "start":0, "duration":117, "slide":4, "view":0}, {"id":0, "start":0, "duration":12, "slide":1, "view":0}, {"id":0, "start":0, "duration":41, "slide":2, "view":0}, {"id":0, "start":0, "duration":29, "slide":3, "view":0}, {"id":0, "start":0, "duration":123, "slide":3, "view":0}, {"id":0, "start":0, "duration":417, "slide":2, "view":0}, {"id":0, "start":0, "duration":12, "slide":1, "view":0}, {"id":0, "start":0, "duration":67, "slide":2, "view":0} ];We have to write a function that takes in this array and returns the top n element of the array in another array (top means the object that has the highest value for duration).Therefore, let’s write the code ... Read More
Let’s say, we have an array of literals that contains some duplicate values −const arr = ['Cat', 'Dog', 'Cat', 'Elephant', 'Dog', 'Grapes', 'Dog', 'Lion', 'Grapes', 'Lion'];We are required to write a function that returns the count of unique elements in the array. Will use Array.prototype.reduce() and Array.prototype.lastIndexOf() to do this −Exampleconst arr = ['Cat', 'Dog', 'Cat', 'Elephant', 'Dog', 'Grapes', 'Dog', 'Lion', 'Grapes', 'Lion']; const countUnique = arr => { return arr.reduce((acc, val, ind, array) => { if(array.lastIndexOf(val) === ind){ return ++acc; }; return acc; }, 0); }; console.log(countUnique(arr));OutputThe output in the console will be −5