864. Shortest Path to Get All Keys

You are given an m x n grid grid where:

• ‘.’ is an empty cell.
• ‘#’ is a wall.
• ‘@’ is the starting point.
• Lowercase letters represent keys.
• Uppercase letters represent locks.

You start at the starting point and one move consists of walking one space in one of the four cardinal directions. You cannot walk outside the grid, or walk into a wall.

If you walk over a key, you can pick it up and you cannot walk over a lock unless you have its corresponding key.

For some 1 <= k <= 6, there is exactly one lowercase and one uppercase letter of the first k letters of the English alphabet in the grid. This means that there is exactly one key for each lock, and one lock for each key; and also that the letters used to represent the keys and locks were chosen in the same order as the English alphabet.

Return the lowest number of moves to acquire all keys. If it is impossible, return -1.

694. Number of Distinct Islands

You are given an m x n binary matrix grid. An island is a group of 1’s (representing land) connected 4-directionally (horizontal or vertical.) You may assume all four edges of the grid are surrounded by water.

An island is considered to be the same as another if and only if one island can be translated (and not rotated or reflected) to equal the other.

Return the number of distinct islands.

1263. Minimum Moves to Move a Box to Their Target Location

A storekeeper is a game in which the player pushes boxes around in a warehouse trying to get them to target locations.

The game is represented by an m x n grid of characters grid where each element is a wall, floor, or box.

Your task is to move the box ‘B’ to the target position ‘T’ under the following rules:

• The character ‘S’ represents the player. The player can move up, down, left, right in grid if it is a floor (empty cell).
• The character ‘.’ represents the floor which means a free cell to walk.
• The character ‘#’ represents the wall which means an obstacle (impossible to walk there).
• There is only one box ‘B’ and one target cell ‘T’ in the grid.
• The box can be moved to an adjacent free cell by standing next to the box and then moving in the direction of the box. This is a push.
• The player cannot walk through the box.

Return the minimum number of pushes to move the box to the target. If there is no way to reach the target, return -1.

1130. Minimum Cost Tree From Leaf Values

Given an array arr of positive integers, consider all binary trees such that:

• Each node has either 0 or 2 children;
• The values of arr correspond to the values of each leaf in an in-order traversal of the tree.
• The value of each non-leaf node is equal to the product of the largest leaf value in its left and right subtree, respectively.
  Among all possible binary trees considered, return the smallest possible sum of the values of each non-leaf node. It is guaranteed this sum fits into a 32-bit integer.

A node is a leaf if and only if it has zero children.

1553. Minimum Number of Days to Eat N Oranges

There are n oranges in the kitchen and you decided to eat some of these oranges every day as follows:

• Eat one orange.
• If the number of remaining oranges n is divisible by 2 then you can eat n / 2 oranges.
• If the number of remaining oranges n is divisible by 3 then you can eat 2 * (n / 3) oranges.

You can only choose one of the actions per day.

Given the integer n, return the minimum number of days to eat n oranges.

996. Number of Squareful Arrays

An array is squareful if the sum of every pair of adjacent elements is a perfect square.

Given an integer array nums, return the number of permutations of nums that are squareful.

Two permutations perm1 and perm2 are different if there is some index i such that perm1[i] != perm2[i].

1680. Concatenation of Consecutive Binary Numbers

Given an integer n, return the decimal value of the binary string formed by concatenating the binary representations of 1 to n in order, modulo 109 + 7.

1157. Online Majority Element In Subarray

Design a data structure that efficiently finds the majority element of a given subarray.

The majority element of a subarray is an element that occurs threshold times or more in the subarray.

Implementing the MajorityChecker class:

• MajorityChecker(int[] arr) Initializes the instance of the class with the given array arr.
• int query(int left, int right, int threshold) returns the element in the subarray arr[left…right] that occurs at least threshold times, or -1 if no such element exists.

1102. Path With Maximum Minimum Value

Given an m x n integer matrix grid, return the maximum score of a path starting at (0, 0) and ending at (m - 1, n - 1) moving in the 4 cardinal directions.

The score of a path is the minimum value in that path.

• For example, the score of the path 8 → 4 → 5 → 9 is 4.

2143. Choose Numbers From Two Arrays in Range

You are given two 0-indexed integer arrays nums1 and nums2 of length n.

A range [l, r] (inclusive) where 0 <= l <= r < n is balanced if:

• For every i in the range [l, r], you pick either nums1[i] or nums2[i].
• The sum of the numbers you pick from nums1 equals to the sum of the numbers you pick from nums2 (the sum is considered to be 0 if you pick no numbers from an array).

Two balanced ranges from [l1, r1] and [l2, r2] are considered to be different if at least one of the following is true:

• l1 != l2
• r1 != r2
• nums1[i] is picked in the first range, and nums2[i] is picked in the second range or vice versa for at least one i.

Return the number of different ranges that are balanced. Since the answer may be very large, return it modulo 109 + 7.