[AtCoder] E - Toward 0Read more
[AtCoder] E - Weighted Tic-Tac-ToeRead more
[AtCoder] E - Minimize Sum of DistancesRead more
[AtCoder] F - Exchange GameRead more
[AtCoder] G - Another Shuffle WindowRead more
[LeetCode] Defuse the Bomb

1652. Defuse the Bomb

You have a bomb to defuse, and your time is running out! Your informer will provide you with a circular array code of length of n and a key k.

To decrypt the code, you must replace every number. All the numbers are replaced simultaneously.

  • If k > 0, replace the ith number with the sum of the next k numbers.
  • If k < 0, replace the ith number with the sum of the previous k numbers.
  • If k == 0, replace the ith number with 0.

As code is circular, the next element of code[n-1] is code[0], and the previous element of code[0] is code[n-1].

Given the circular array code and an integer key k, return the decrypted code to defuse the bomb!

Read more
[LeetCode] Find the Number of K-Even Arrays

3339. Find the Number of K-Even Arrays

You are given three integers n, m, and k.

An array arr is called k-even if there are exactly k indices such that, for each of these indices i (0 <= i < n - 1):

  • (arr[i] * arr[i + 1]) - arr[i] - arr[i + 1] is even.

Return the number of possible k-even arrays of size n where all elements are in the range [1, m].

Since the answer may be very large, return it modulo 109 + 7.

Read more
[LeetCode] Minimize the Maximum Adjacent Element Difference

3357. Minimize the Maximum Adjacent Element Difference

You are given an array of integers nums. Some values in nums are missing and are denoted by -1.

You can choose a pair of positive integers (x, y) exactly once and replace each missing element with either x or y.

You need to minimize the maximum absolute difference between adjacent elements of nums after replacements.

Return the minimum possible difference.

Read more
[LeetCode] Zero Array Transformation II

3356. Zero Array Transformation II

You are given an integer array nums of length n and a 2D array queries where queries[i] = [li, ri, vali].

Each queries[i] represents the following action on nums:

  • Decrement the value at each index in the range [li, ri] in nums by at most vali.
  • The amount by which each value is decremented can be chosen independently for each index.

A Zero Array is an array with all its elements equal to 0.

Return the minimum possible non-negative value of k, such that after processing the first k queries in sequence, nums becomes a Zero Array. If no such k exists, return -1.

Read more
[LeetCode] Zero Array Transformation I

3355. Zero Array Transformation I

You are given an integer array nums of length n and a 2D array queries, where queries[i] = [li, ri].

For each queries[i]:

  • Select a subset of indices within the range [li, ri] in nums.
  • Decrement the values at the selected indices by 1.

A Zero Array is an array where all elements are equal to 0.

Return true if it is possible to transform nums into a Zero Array after processing all the queries sequentially, otherwise return false.

A subset of an array is a selection of elements (possibly none) of the array.

Read more