Given an m x n grid of characters board and a string word, return true if word exists in the grid.
The word can be constructed from letters of sequentially adjacent cells, where adjacent cells are horizontally or vertically neighboring. The same letter cell may not be used more than once.
307. Range Sum Query - Mutable
Given an integer array nums, handle multiple queries of the following types:
- Update the value of an element in nums.
- Calculate the sum of the elements of nums between indices left and right inclusive where left <= right.
Implement the NumArray class:
- NumArray(int[] nums) Initializes the object with the integer array nums.
- void update(int index, int val) Updates the value of nums[index] to be val.
- int sumRange(int left, int right) Returns the sum of the elements of nums between indices left and right inclusive (i.e. nums[left] + nums[left + 1] + … + nums[right]).
1567. Maximum Length of Subarray With Positive Product
Given an array of integers nums, find the maximum length of a subarray where the product of all its elements is positive.
A subarray of an array is a consecutive sequence of zero or more values taken out of that array.
Return the maximum length of a subarray with positive product.
842. Split Array into Fibonacci Sequence
Given a string S of digits, such as S = “123456579”, we can split it into a Fibonacci-like sequence [123, 456, 579].
Formally, a Fibonacci-like sequence is a list F of non-negative integers such that:
- 0 <= F[i] <= 2^31 - 1, (that is, each integer fits a 32-bit signed integer type);
- F.length >= 3;
- and F[i] + F[i+1] = F[i+2] for all 0 <= i < F.length - 2.
Also, note that when splitting the string into pieces, each piece must not have extra leading zeroes, except if the piece is the number 0 itself.
Return any Fibonacci-like sequence split from S, or return [] if it cannot be done.
Given an integer n (in base 10) and a base k, return the sum of the digits of n after converting n from base 10 to base k.
After converting, each digit should be interpreted as a base 10 number, and the sum should be returned in base 10.
1839. Longest Substring Of All Vowels in Order
A string is considered beautiful if it satisfies the following conditions:
- Each of the 5 English vowels (‘a’, ‘e’, ‘i’, ‘o’, ‘u’) must appear at least once in it.
- The letters must be sorted in alphabetical order (i.e. all ‘a’s before ‘e’s, all ‘e’s before ‘i’s, etc.).
For example, strings “aeiou” and “aaaaaaeiiiioou” are considered beautiful, but “uaeio”, “aeoiu”, and “aaaeeeooo” are not beautiful.
Given a string word consisting of English vowels, return the length of the longest beautiful substring of word. If no such substring exists, return 0.
A substring is a contiguous sequence of characters in a string.
1838. Frequency of the Most Frequent Element
The frequency of an element is the number of times it occurs in an array.
You are given an integer array nums and an integer k. In one operation, you can choose an index of nums and increment the element at that index by 1.
Return the maximum possible frequency of an element after performing at most k operations.
You want to build n new buildings in a city. The new buildings will be built in a line and are labeled from 1 to n.
However, there are city restrictions on the heights of the new buildings:
- The height of each building must be a non-negative integer.
- The height of the first building must be 0.
- The height difference between any two adjacent buildings cannot exceed 1.
Additionally, there are city restrictions on the maximum height of specific buildings. These restrictions are given as a 2D integer array restrictions where restrictions[i] = [idi, maxHeighti] indicates that building idi must have a height less than or equal to maxHeighti.
It is guaranteed that each building will appear at most once in restrictions, and building 1 will not be in restrictions.
Return the maximum possible height of the tallest building.
Implement a SnapshotArray that supports the following interface:
- SnapshotArray(int length) initializes an array-like data structure with the given length. Initially, each element equals 0.
- void set(index, val) sets the element at the given index to be equal to val.
- int snap() takes a snapshot of the array and returns the snap_id: the total number of times we called snap() minus 1.
- int get(index, snap_id) returns the value at the given index, at the time we took the snapshot with the given snap_id
Given an array, rotate the array to the right by k steps, where k is non-negative.