ML studying

[Problem] You are given an integer array nums. You are initially positioned at the array's first index, and each element in the array represents your maximum jump length at that position. Return true if you can reach the last index, or false otherwise. [Explanation] In this problem, just check possibility whether reaching the last location using previous numbers. [Solution] Sometimes, a simplist..

[Problem] Given an array nums with n objects colored red, white, or blue, sort them in-place so that objects of the same color are adjacent, with the colors in the order red, white, and blue. We will use the integers 0, 1, and 2 to represent the color red, white, and blue, respectively. You must solve this problem without using the library's sort function. 빨강색(0), 하얀색(1), 파란색(2)이 랜덤하게 섞여있는 배열을 빨..

[Problem] You are given a 0-indexed array of integers nums of length n. You are initially positioned at nums[0]. Each element nums[i] represents the maximum length of a forward jump from index i. In other words, if you are at nums[i], you can jump to any nums[i + j] where: 0 idx: break if arr[j][1] + 1

[Problem] There is an integer array nums sorted in ascending order (with distinct values). Prior to being passed to your function, nums is possibly rotated at an unknown pivot index k (1

[Problem] Given two strings needle and haystack, return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. [Solution] It is quite simple! 1) First, check a length of 'haystack' is shorter than a length of 'needle'. If it is, return -1. 2) Second, before checking all characters between haystack and needle, I checked the last character and the first t..

[Problem] Given an integer array nums, return all the triplets [nums[i], nums[j], nums[k]] such that i != j, i != k, and j != k, (I thought it was the value of nums[i], but it was just index! Don't get confused. Maybe I am the only one confused?) and nums[i] + nums[j] + nums[k] == 0. Notice that the solution set must not contain duplicate triplets. [Solution] Actually, I tried several methods. B..

[Problem] Given a signed 32-bit integer x, return x with its digits reversed. If reversing x causes the value to go outside the signed 32-bit integer range [-231, 231 - 1], then return 0. Assume the environment does not allow you to store 64-bit integers (signed or unsigned). [Solution] It is quite simple problem. just reverse digits like [123 > -123] In my case, I think int such as string. So, ..

[Problem] The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility) [Explanation] After arranging string to zigzag, combine zigzagged string as one. There is a given number of rows. So I can arrange string in codition of rows and combine as one For example, 'PAYPALISHIRING' and a gi..

https://leetcode.com/problems/longest-palindromic-substring/ Longest Palindromic Substring - LeetCode Longest Palindromic Substring - Given a string s, return the longest palindromic substring in s. Example 1: Input: s = "babad" Output: "bab" Explanation: "aba" is also a valid answer. Example 2: Input: s = "cbbd" Output: "bb" Constraints: * 1