Problem The array-form of an integer num is an array representing its digits in left to right order. For example, for num = 1321, the array form is [1,3,2,1]. Given num, the array-form of an integer, and an integer k, return the array-form of the integer num + k. Examples Example 1: Input: num = [1,2,0,0], k = 34 Output: [1,2,3,4] Explanation: 1200 + 34 = 1234 ...
Problem Given a positive integer num, write a function which returns True if num is a perfect square else False. Follow up: Do not use any built-in library function such as sqrt. Examples Example 1: Input: num = 16 Output: true Example 2: Input: num = 14 Output: false ...
Problem You are given two linked lists representing two non-negative numbers. Problem 1 - The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list. Input: (2 -> 4 -> 3) + (5 -> 6 -> 4) Output: 7 -> 0 -> 8 ...
Problem Given an integer n, return true if n is a perfect number, otherwise return false. Definition A perfect number is a natural number that is equal to the sum of its positive divisors, excluding the number itself. A divisor of an integer x is an integer that can divide x evenly. The first perfect numbers are 6, 28, 496, 8128 and all of them are in form $$ 2^{n-1}.(2^n - 1)$$ ...
Problem Given an integer numRows, return the first numRows of Pascal’s triangle. Examples Example 1: ...
Problem You have n coins and you want to build a staircase with these coins. The staircase consists of k rows where the ith row has exactly i coins. The last row of the staircase may be incomplete. Given the integer n, return the number of complete rows of the staircase you will build. Examples Example 1: $$ \begin{matrix} \colorbox{orange} $ \\ \colorbox{orange} $ & \colorbox{orange} $ \\ \colorbox{orange} $ & \colorbox{orange} $ &\colorbox{white} 0 \end{matrix} $$ ...
Problem Given a list of non-negative integers nums, arrange them such that they form the largest number and return it. Since the result may be very large, so you need to return a string instead of an integer. Example Example 1: Input: nums = [10,2] Output: "210" Example 2: Input: nums = [3,30,34,5,9] Output: "9534330" ...
Problem Write a program to check whether a given number is an ugly number. Ugly Number Definition Examples Example 1: Input: n = 6 Output: true Explanation: 6 = 2 × 3 Example 2: Input: n = 1 Output: true Explanation: 1 has no prime factors, therefore all of its prime factors are limited to 2, 3, and 5. ...
Problem Given a string s representing a valid expression, implement a basic calculator to evaluate it, and return the result of the evaluation. Note: You are not allowed to use any built-in function which evaluates strings as mathematical expressions, such as eval(). Examples Example 1: Input: s = "3+2*2" Output: 7 Example 2: Input: s = " 3/2 " Output: 1 ...
Problem Given a string s representing a valid expression, implement a basic calculator to evaluate it, and return the result of the evaluation. Note: You are not allowed to use any built-in function which evaluates strings as mathematical expressions, such as eval().%% %% Examples Example 1: Input: s = "1 + 1" Output: 2 ...