Data-Structures-and-Algorithms-Project

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CITS2200 - Data Structures and Algorithms (2020/Sem-1)

The University of Western Australia

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Problem Specification

You must implement the following four functions, and provide a report on your implementations. Each function is worth a different number of marks for a total of 20 marks. Details for what the mark breakdowns mean are provided below.

All questions work with a greyscale image specified as a 2D int array. The array is indexed first by row, then by column. Every row in the array will be the same length. Every element in the array will be non-negative and no greater than 255. A value of 0 represents a black pixel, and a value of 255 represents white, with shades of grey in between.

Time complexity specifications use R for number of rows, C for number of columns, and P = R\*C for number of pixels.

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public int floodFillCount(int\[]\[] image, int row, int col)

Compute the number of pixels that change when performing a black flood-fill from the pixel at ( row , col ) in the given image. A flood-fill operation changes the selected pixel and all contiguous pixels of the same colour to the specified colour. A pixel is considered part of a contiguous region of the same colour if it is exactly one pixel up/down/left/right of another pixel in the region.

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public int brightestSquare(int\[]\[] image, int k)

Compute the total brightness of the brightest exactly k\*k square that appears in the given image. The total brightness of a square is defined as the sum of its pixel values. You may assume that k is positive, no greater than R or C , and no greater than 2048.

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public int darkestPath(int\[]\[] image, int ur, int uc, int vr, int vc)

Compute the maximum brightness that MUST be encountered when drawing a path from the pixel at ( ur , uc ) to the pixel at ( vr , vc ). The path must start at ( ur , uc ) and end at ( vr , vc ), and may only move one pixel up/down/left/right at a time in between. The brightness of a path is considered to be the value of the brightest pixel that the path ever touches. This includes the start and end pixels of the path.

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public int\[] brightestPixelsInRowSegments(int\[]\[] image, int\[]\[] queries)

Compute the results of a list of queries on the given image. Each query will be a three-element int array {r, l, u} defining a row segment. You may assume l < u. A row segment is a set of pixels ( r , c ) such that r is as defined, l <= c , and c < u. For each query, find the value of the brightest pixel in the specified row segment. Return the query results in the same order as the queries are given.

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Testing

Your code must compile correctly when compiled with:

javac Project.java MyProject.java SampleProjectUnitTest.java

After compiling, you can test your code using the provided sample unit tests with:

java SampleProjectUnitTest

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NOTE: THIS PROJECT WAS PART OF THE DATA STRUCTURES AND ALGORITHMS UNIT (CITS2200) AT THE UNIVERSITY OF WESTERN AUSTRALIA. SOME SAMPLE CODE FOR THE PROJECT INTERFACE/TESTER WAS PROVIDED BY Andrew Gozzard andrew.gozzard@uwa.edu.au.