Do it for FUN | SUMFIのBlog

9th Place on LC Contest 2022-11-26|Etc|SUMFIの一日

후기

[LeetCode] Count Palindromic Subsequences 2022-11-26|PSLeetCode|Problem Solving-Prefix Sum

Given a string of digits s, return the number of palindromic subsequences of s having length 5. Since the answer may be very large, return it modulo 109 + 7.

Note:

A string is palindromic if it reads the same forward and backward.

A subsequence is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters.

[LeetCode] Minimum Penalty for a Shop 2022-11-26|PSLeetCode|Problem Solving-Math

2483. Minimum Penalty for a Shop

You are given the customer visit log of a shop represented by a 0-indexed string customers consisting only of characters ‘N’ and ‘Y’:

if the ith character is ‘Y’, it means that customers come at the ith hour

whereas ‘N’ indicates that no customers come at the ith hour.

If the shop closes at the jth hour (0 <= j <= n), the penalty is calculated as follows:

For every hour when the shop is open and no customers come, the penalty increases by 1.

For every hour when the shop is closed and customers come, the penalty increases by 1.

Return the earliest hour at which the shop must be closed to incur a minimum penalty.

Note that if a shop closes at the jth hour, it means the shop is closed at the hour j.

[LeetCode] Difference Between Ones and Zeros in Row and Column 2022-11-26|PSLeetCode|Problem Solving-Matrix

2482. Difference Between Ones and Zeros in Row and Column

You are given a 0-indexed m x n binary matrix grid.

A 0-indexed m x n difference matrix diff is created with the following procedure:

Let the number of ones in the ith row be onesRowi.

Let the number of ones in the jth column be onesColj.

Let the number of zeros in the ith row be zerosRowi.

Let the number of zeros in the jth column be zerosColj.

diff[i][j] = onesRowi + onesColj - zerosRowi - zerosColj

Return the difference matrix diff.

[LeetCode] Minimum Cuts to Divide a Circle 2022-11-26|PSLeetCode|Problem Solving-Geometry

2481. Minimum Cuts to Divide a Circle

A valid cut in a circle can be:

A cut that is represented by a straight line that touches two points on the edge of the circle and passes through its center, or

A cut that is represented by a straight line that touches one point on the edge of the circle and its center.

Some valid and invalid cuts are shown in the figures below.