Problem A sentence is a string of single-space separated words where each word consists only of lowercase letters. A word is uncommon if it appears exactly once in one of the sentences, and does not appear in the other sentence. Given two sentences s1 and s2, return a list of all the uncommon words. You may return the answer in any order. Examples Example 1: ...
Problem Given three 32-bit integers x, y, and b, return x if b is 1 and y if b is 0, using only mathematical or bit operations. You can assume b can only be 1 or 0. Solution Method 1 - Using bitwise masks The core idea is to leverage bitwise operations to create masks based on the value of b, which will then be used to select either x or y. ...
Problem You are given an array of integers nums and the head of a linked list. Return the head of the modified linked list after removing all nodes from the linked list that have a value that exists in nums. Examples Example 1: graph LR A[1]:::toBeDeleted --> B[2]:::toBeDeleted --> C[3]:::toBeDeleted --> D[4] --> E[5] classDef toBeDeleted fill:#ffcccc,stroke:#ff0000; ...
Problem There are n students in a class numbered from 0 to n - 1. The teacher will give each student a problem starting with the student number 0, then the student number 1, and so on until the teacher reaches the student number n - 1. After that, the teacher will restart the process, starting with the student number 0 again. You are given a 0-indexed integer array chalk and an integer k. There are initially k pieces of chalk. When the student number i is given a problem to solve, they will use chalk[i] pieces of chalk to solve that problem. However, if the current number of chalk pieces is strictly less than chalk[i], then the student number i will be asked to replace the chalk. ...
Problem Given an array of integers nums, sort the array in increasing order based on the frequency of the values. If multiple values have the same frequency, sort them in decreasing order. Return the sorted array. Examples Example 1: Input: nums = [1,1,2,2,2,3] Output: [3,1,1,2,2,2] Explanation: '3' has a frequency of 1, '1' has a frequency of 2, and '2' has a frequency of 3. ...
Problem You are given an array of strings names, and an array heights that consists of distinct positive integers. Both arrays are of length n. For each index i, names[i] and heights[i] denote the name and height of the ith person. Return names sorted in descending order by the people’s heights. Examples Example 1: Input: names = ["Mary","John","Emma"], heights = [180,165,170] Output: ["Mary","Emma","John"] Explanation: Mary is the tallest, followed by Emma and John. ...
Java strings are immutable ⇨ Once created, the content of the string cannot be changed. Any methods that seem to modify a String object, like concat, actually create a new String object with the desired changes. The original String object remains unchanged. Here are a set of diagrams to illustrate Java String’s immutability. Initializing string We can declare a string s: String s = "hello"; ...
Problem Given two non-negative integers, num1 and num2 represented as string, return the sum of num1 and num2 as a string. You must solve the problem without using any built-in library for handling large integers (such as BigInteger). You must also not convert the inputs to integers directly. Examples Example 1: Input: num1 = "11", num2 = "123" Output: "134" ...
Problem Given two integers dividend and divisor, divide two integers without using multiplication, division, and mod operator. The integer division should truncate toward zero, which means losing its fractional part. For example, 8.345 would be truncated to 8, and -2.7335 would be truncated to -2. Return the quotient after dividing dividend by divisor. Note: Assume we are dealing with an environment that could only store integers within the 32-bit signed integer range: [−2^31, 2^31 − 1]. For this problem, if the quotient is strictly greater than 2^31 - 1, then return 2^31 - 1, and if the quotient is strictly less than -2^31, then return -2^31. ...
Problem Implement the myAtoi(string s) function, which converts a string to a 32-bit signed integer. The algorithm for myAtoi(string s) is as follows: Whitespace: Ignore any leading whitespace (" "). Signedness: Determine the sign by checking if the next character is '-' or '+', assuming positivity is neither present. Conversion: Read the integer by skipping leading zeros until a non-digit character is encountered or the end of the string is reached. If no digits were read, then the result is 0. Rounding: If the integer is out of the 32-bit signed integer range [-2^31, 2^31 - 1], then round the integer to remain in the range. Specifically, integers less than -2^31 should be rounded to -2^31, and integers greater than 2^31 - 1 should be rounded to 2^31 - 1. Return the integer as the final result. ...