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ProblemGiven two strings s and t, return true if s is a subsequence of t, or false otherwise. A subsequence of a string is a new string that is formed from the original string by deleting some (can be none) of the characters without disturbing the relative positions of the remaining characters. (i.e., "ace" is a subsequence of "abcde" while "aec" is not). Example 1: 123Input: s = "abc", t = "ahbgdc"Output: true Example 2: 123Input: s = "axc ...

ProblemGiven a binary array nums, you should delete one element from it. Return the size of the longest non-empty subarray containing only 1‘s in the resulting array. Return 0 if there is no such subarray. Example 1: 1234Input: nums = [1,1,0,1]Output: 3Explanation: After deleting the number in position 2, [1,1,1] contains 3 numbers with value of 1's. Example 2: 1234Input: nums = [0,1,1,1,0,1,1,0,1]Output: 5Explanation: After deleting the number in position 4, [0,1,1,1,1,1,0,1] longest suba ...

ProblemGiven a string s and an integer k, return the maximum number of vowel letters in any substring of s with length k. Vowel letters in English are 'a', 'e', 'i', 'o', and 'u'. Example 1: 1234Input: s = "abciiidef", k = 3Output: 3Explanation: The substring "iii" contains 3 vowel letters. Example 2: 1234Input: s = "aeiou", k = 2Output: 2Explanation: Any substring of length 2 contains 2 vowels. Example 3: 1234Input: s = &qu ...

ProblemYou are given an integer array nums consisting of n elements, and an integer k. Find a contiguous subarray whose length is equal to k that has the maximum average value and return this value. Any answer with a calculation error less than 10-5 will be accepted. Example 1: 1234Input: nums = [1,12,-5,-6,50,3], k = 4Output: 12.75000Explanation: Maximum average is (12 - 5 - 6 + 50) / 4 = 51 / 4 = 12.75 Example 2: 123Input: nums = [5], k = 1Output: 5.00000 Constraints: n == nums.length 1 < ...

ProblemGiven an array of intervals intervals where intervals[i] = [starti, endi], return the minimum number of intervals you need to remove to make the rest of the intervals non-overlapping. Example 1: 1234Input: intervals = [[1,2],[2,3],[3,4],[1,3]]Output: 1Explanation: [1,3] can be removed and the rest of the intervals are non-overlapping. Example 2: 1234Input: intervals = [[1,2],[1,2],[1,2]]Output: 2Explanation: You need to remove two [1,2] to make the rest of the intervals non-overlapping. ...

ProblemThere 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 <= k < nums.length) such that the resulting array is [nums[k], nums[k+1], ..., nums[n-1], nums[0], nums[1], ..., nums[k-1]] (0-indexed). For example, [0,1,2,4,5,6,7] might be rotated at pivot index 3 and become [4,5,6,7,0,1,2]. Given the array nums after the possible rotation and an integer target, return the ...

ProblemGiven an array of integers nums and an integer target, return indices of the two numbers such that they add up to target. You may assume that each input would have exactly one solution, and you may not use the same element twice. You can return the answer in any order. Example 1: 1234Input: nums = [2,7,11,15], target = 9Output: [0,1]Explanation: Because nums[0] + nums[1] == 9, we return [0, 1]. Example 2: 123Input: nums = [3,2,4], target = 6Output: [1,2] Example 3: 123Input: nums = [3,3 ...

ProblemThe thief has found himself a new place for his thievery again. There is only one entrance to this area, called root. Besides the root, each house has one and only one parent house. After a tour, the smart thief realized that all houses in this place form a binary tree. It will automatically contact the police if two directly-linked houses were broken into on the same night. Given the root of the binary tree, return the maximum amount of money the thief can rob without alerting the police ...

ProblemGiven an integer array nums, find the subarray with the largest sum, and return its sum . Example 1: 1234Input: nums = [-2,1,-3,4,-1,2,1,-5,4]Output: 6Explanation: The subarray [4,-1,2,1] has the largest sum 6. Example 2: 1234Input: nums = [1]Output: 1Explanation: The subarray [1] has the largest sum 1. Example 3: 1234Input: nums = [5,4,-1,7,8]Output: 23Explanation: The subarray [5,4,-1,7,8] has the largest sum 23. Constraints: 1 <= nums.length <= 10^5 10^4 <= nums[i] <= 1 ...

ProblemGiven an integer n, return the number of trailing zeroes in n!. Note that n! = n * (n - 1) * (n - 2) * ... * 3 * 2 * 1. Example 1: 1234Input: n = 3Output: 0Explanation: 3! = 6, no trailing zero. Example 2: 1234Input: n = 5Output: 1Explanation: 5! = 120, one trailing zero. Example 3: 123Input: n = 0Output: 0 Constraints: 0 <= n <= 10^4 Follow up: Could you write a solution that works in logarithmic time complexity? Solve這題先搞懂 trailing zeroes，是指尾巴的0 要計算尾巴有幾個0很簡單就是算其中乘了幾次(5*2) 由於每 ...