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ProblemWe are required to write a JavaScript function that takes in a number n. Our function should return an array showing all the ways of balancing n parenthesis.For example, for n = 3, the output will be −["()()()","(())()","()(())","(()())","((()))"]ExampleFollowing is the code − Live Democonst res = []; const buildcombination = (left, right, str) => { if (left === 0 && right === 0) { res.push(str); } if (left > 0) { buildcombination(left-1, right+1, str+"("); } if (right > 0) { buildcombination(left, right-1, str+")"); } } buildcombination(3, 0, ""); console.log(res);OutputFollowing is the console output −[ '((()))', '(()())', '(())()', '()(())', '()()()' ]
When it is required to calculate the length of a string without using library methods, a counter is used to increment every time an element of the string is encountered.Below is the demonstration of the same −Example Live Demomy_string = "Hi Will" print("The string is :") print(my_string) my_counter=0 for i in my_string: my_counter=my_counter+1 print("The length of the string is ") print(my_counter)OutputThe string is : Hi Will The length of the string is 7ExplanationA string is defined, and is displayed on the console.A counter is initialized to 0.The string is iterated over, and after every element is iterated over, the counter ... Read More
When it is required to remove a specific index character from a string which isn’t empty, it can be iterated over, and when the index doesn’t match, that character can be stored in another string.Below is the demonstration of the same −Example Live Demomy_string = "Hi there how are you" print("The string is :") print(my_string) index_removed = 2 changed_string = '' for char in range(0, len(my_string)): if(char != index_removed): changed_string += my_string[char] print("The string after removing ", index_removed, "nd character is : ") print(changed_string)OutputThe string is : Hi there how are you The ... Read More
When it is required to find the maximum sub array using Kadane’s algorithm, a method is defined that helps find the maximum of the sub array. Iterators are used to keep track of the maximum sub array.Below is the demonstration of the same −Example Live Demodef find_max_sub_array(my_list, beg, end): max_end_at_i = max_seen_till_now = my_list[beg] max_left_at_i = max_left_till_now = beg max_right_till_now = beg + 1 for i in range(beg + 1, end): if max_end_at_i > 0: max_end_at_i += my_list[i] else: max_end_at_i = my_list[i] ... Read More
ProblemWe are required to write a JavaScript function that takes in an array of literals that might contain some 0s. Our function should tweak the array such that all the zeroes are pushed to the end and all non-zero elements hold their relative positions.ExampleFollowing is the code − Live Democonst arr = [5, 0, 1, 0, -3, 0, 4, 6]; const moveAllZero = (arr = []) => { const res = []; let currIndex = 0; for(let i = 0; i < arr.length; i++){ const el = arr[i]; if(el === 0){ res.push(0); }else{ res.splice(currIndex, undefined, el); currIndex++; }; }; return res; }; console.log(moveAllZero(arr));OutputFollowing is the console output −[ 5, 1, -3, 4, 6, 0, 0, 0 ]
ProblemWe are required to write a JavaScript function that takes in an array of integers arr. Our function should return the string ‘odd’ if the sum of all the elements of the array is odd or ‘even’ if it’s even.ExampleFollowing is the code − Live Democonst arr = [5, 1, 8, 4, 6, 9]; const assignSum = (arr = []) => { const sum = arr.reduce((acc, val) => { return acc + val; }, 0); const isSumEven = sum % 2 === 0; return isSumEven ? 'even' : 'odd'; }; console.log(assignSum(arr));OutputFollowing is the console output −odd
ProblemWe are required to write a JavaScript function that takes in a number n. Our function should construct and return an array of N * N order (2-D array), in which the 1s take all the spiralling positions starting from [0, 0] and all the 0s take non-spiralling positions.Therefore, for n = 5, the output will look like −[ [ 1, 1, 1, 1, 1 ], [ 0, 0, 0, 0, 1 ], [ 1, 1, 1, 0, 1 ], [ 1, 0, 0, 0, 1 ], [ 1, 1, 1, 1, 1 ] ]ExampleFollowing ... Read More
ProblemWe are required to write a JavaScript function that lives on the prototype object of the string class.This function should simply change case of all the alphabets present in the string to uppercase and return the new string.ExampleFollowing is the code − Live Democonst str = 'This is a lowercase String'; String.prototype.customToUpperCase = function(){ const legend = 'abcdefghijklmnopqrstuvwxyz'; const UPPER = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'; let res = ''; for(let i = 0; i < this.length; i++){ const el = this[i]; const index = legend.indexOf(el); if(index !== -1){ ... Read More
ProblemSuppose the following number name string −const str = 'TOWNE';If we rearrange this string, we can find two number names in it 2 (TWO) and 1 (ONE).Therefore, we expect an output of 21We are required to write a JavaScript function that takes in one such string and returns the numbers present in the string.ExampleFollowing is the code − Live Democonst str = 'TOWNE'; const findNumber = (str = '') => { function stringPermutations(str) { const res = []; if (str.length == 1) return [str]; if (str.length == 2) return [str, str[1]+str[0]]; ... Read More
ProblemWe are required to write a JavaScript function that takes in an array of numbers (positive and negative). Our function should calculate and return the sum of all the positive numbers present in the array.ExampleFollowing is the code − Live Democonst arr = [5, -5, -3, -5, -7, -8, 1, 9]; const sumPositives = (arr = []) => { const isPositive = num => typeof num === 'number' && num > 0; const res = arr.reduce((acc, val) => { if(isPositive(val)){ acc += val; }; return acc; }, 0); return res; }; console.log(sumPositives(arr));OutputFollowing is the console output −15