Minimum Cost to Make a Valid Path in a Grid — Algorithm Visualization & Coding Challenge

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Understanding Minimum Cost to Make a Valid Path in a Grid
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Problem Overview

Problem Summary: Minimum Cost to Make a Valid Path in a Grid

You are given a grid with m x n dimensions, where each cell contains an arrow pointing to one of four directions:

  1. Right (1): Move to the cell on the right.
  2. Left (2): Move to the cell on the left.
  3. Down (3): Move to the cell below.
  4. Up (4): Move to the cell above.
  • You start at the top-left corner (0, 0) and aim to reach the bottom-right corner (m-1, n-1) by following the arrows.
  • If necessary, you can modify the arrow in a cell at a cost of 1.
  • The goal is to calculate the minimum cost required to create at least one valid path from the start to the end of the grid.

Examples:

  1. Input: [[1,1,1,1],[2,2,2,2],[1,1,1,1],[2,2,2,2]]
    image

    Output: 3

    Explanation: Modify arrows in 3 cells to create a valid path from (0, 0) to (3, 3).

  2. Input: [[1,1,3],[3,2,2],[1,1,4]]

    Output: 0
    Explanation: A valid path already exists without any modifications.

  3. Input: [[1,2],[4,3]]
    Output: 1
    Explanation: Modify one cell's arrow to create a valid path.

Constraints:

  • 1 <= m, n <= 100
  • Each cell contains a value from 1 to 4.
— Written by Saurabh Patil • B.Tech CSE • Software Developer

Categories
leetcode-problem-of-the-day
dp
graphs
java
Reference Link
https://leetcode.com/problems/minimum-cost-to-make-at-least-one-valid-path-in-a-grid/description/

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