[AtCoder] D - Floor FunctionRead more
[AtCoder] C - Many RequirementsRead more
[Codeforces] Round #298 (Div. 2) B. Covered PathRead more
[Codeforces] Round #300 A. Cutting BannerRead more
[Codeforces] Round #300 B. Quasi BinaryRead more
[Codeforces] Round #807 (Div. 2) C. Mark and His Unfinished EssayRead more
[Codeforces] Round #809 (Div. 2) C. Qpwoeirut And The CityRead more
[LeetCode] Minimum Cost Homecoming of a Robot in a Grid

2087. Minimum Cost Homecoming of a Robot in a Grid

There is an m x n grid, where (0, 0) is the top-left cell and (m - 1, n - 1) is the bottom-right cell. You are given an integer array startPos where startPos = [startrow, startcol] indicates that initially, a robot is at the cell (startrow, startcol). You are also given an integer array homePos where homePos = [homerow, homecol] indicates that its home is at the cell (homerow, homecol).

The robot needs to go to its home. It can move one cell in four directions: left, right, up, or down, and it can not move outside the boundary. Every move incurs some cost. You are further given two 0-indexed integer arrays: rowCosts of length m and colCosts of length n.

  • If the robot moves up or down into a cell whose row is r, then this move costs rowCosts[r].
  • If the robot moves left or right into a cell whose column is c, then this move costs colCosts[c].

Return the minimum total cost for this robot to return home.

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[LeetCode] HTML Entity Parser

1410. HTML Entity Parser

HTML entity parser is the parser that takes HTML code as input and replace all the entities of the special characters by the characters itself.

The special characters and their entities for HTML are:

  • Quotation Mark: the entity is " and symbol character is “.
  • Single Quote Mark: the entity is ' and symbol character is ‘.
  • Ampersand: the entity is & and symbol character is &.
  • Greater Than Sign: the entity is > and symbol character is >.
  • Less Than Sign: the entity is &lt; and symbol character is <.
  • Slash: the entity is &frasl; and symbol character is /.

Given the input text string to the HTML parser, you have to implement the entity parser.

Return the text after replacing the entities by the special characters.

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[LeetCode] Fraction Addition and Subtraction

592. Fraction Addition and Subtraction

Given a string expression representing an expression of fraction addition and subtraction, return the calculation result in string format.

The final result should be an irreducible fraction. If your final result is an integer, change it to the format of a fraction that has a denominator 1. So in this case, 2 should be converted to 2/1.

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