leetcode
A string is a valid parentheses string (denoted VPS) if it meets one of the following: * It is an empty string "", or a single character not equal to "(" or ")", * It can be written as AB (A concatenated with B), where A and B are
leetcode
The Leetcode file system keeps a log each time some user performs a change folder operation. The operations are described below: * "../" : Move to the parent folder of the current folder. (If you are already in the main folder, remain in the same folder). * "./" : Remain in the
leetcode
There are 3n piles of coins of varying size, you and your friends will take piles of coins as follows: * In each step, you will choose any 3 piles of coins (not necessarily consecutive). * Of your choice, Alice will pick the pile with the maximum number of coins. * You will
leetcode
Given a string s of lower and upper case English letters. A good string is a string which doesn't have two adjacent characters s[i] and s[i + 1] where: * 0 <= i <= s.length - 2 * s[i] is a lower-case letter and s[i + 1]
leetcode
Given a string s and an integer array indices of the same length. The string s will be shuffled such that the character at the ith position moves to indices[i] in the shuffled string. Return the shuffled string. Example 1: Input: s = "codeleet", indices = [4,5,6,
leetcode
Given an array of integers nums. A pair (i,j) is called good if nums[i] == nums[j] and i < j. Return the number of good pairs. Example 1: Input: nums = [1,2,3,1,1,3] Output: 4 Explanation: There are 4 good pairs (0,3), (0,4)
leetcode
Given a date string in the form Day Month Year, where: * Day is in the set {"1st", "2nd", "3rd", "4th", ..., "30th", "31st"}. * Month is in the set {"Jan", "Feb", "Mar", "Apr&
leetcode
Given an array of strings names of size n. You will create n folders in your file system such that, at the ith minute, you will create a folder with the name names[i]. Since two files cannot have the same name, if you enter a folder name which is
leetcode
Given an integer n and an integer start. Define an array nums where nums[i] = start + 2*i (0-indexed) and n == nums.length. Return the bitwise XOR of all elements of nums. Example 1: Input: n = 5, start = 0 Output: 8 Explanation: Array nums is equal to [0, 2, 4,
leetcode
Given an array nums. We define a running sum of an array as runningSum[i] = sum(nums[0]…nums[i]). Return the running sum of nums. Example 1: Input: nums = [1,2,3,4] Output: [1,3,6,10] Explanation: Running sum is obtained as follows: [1, 1+2, 1+
leetcode
Given the array prices where prices[i] is the price of the ith item in a shop. There is a special discount for items in the shop, if you buy the ith item, then you will receive a discount equivalent to prices[j] where j is the minimum index such
leetcode
Given the array nums consisting of 2n elements in the form [x1,x2,...,xn,y1,y2,...,yn]. Return the array in the form [x1,y1,x2,y2,...,xn,yn]. Example 1: Input: nums = [2,5,1,3,4,7], n = 3 Output: [2,3,5,4,1,7] Explanation: Since