- In the problem zero three folder of my testing site,…I've created a file called queens dot php.…You can find this in the exercise files…for this video.…It contains some simple code to keep track…of how long the script takes to execute…and defines a constant called board size…and sets its value to eight.…That's the size of the chessboard.…We know that two queens can never be in the same…row or column, so we can use a loop to represent…the eight rows, each of which will contain…a queen in a different column.…
So let's have that loop.…We'll initialize row at zero.…We'll use the board size to control the loop,…and increment row each time we go through the loop.…Inside there we'll create an array called layout.…We'll give it the index of row, and then assign…the value of one, and then use the bit wise…shift left operator and the value of row.…
So this will generate binary numbers that shift…the bits the same number of places as the value…of the counter row.…The first time the loop runs row is zero,…so no bits are moved.…
Author
Updated
12/16/2014Released
7/15/2014David introduces challenges and provides an overview of his solutions in PHP. Challenges include topics such as statistical analysis, searching directories for images, and accessing peripheral devices.
Visit other courses in the series to see how to solve the exact same challenges in languages like C#, C++, Java, Python, and Ruby.
Skill Level Intermediate
Duration
Views
Q: I'm encountering script errors message with the prime_dates.php file used in the "Priming the date_record column" movie in this course. How can I resolve these errors?
A: To avoid script errors, use bindValue() instead of bindParam() in
Line 9 of the prime_dates.php file. You can also download the latest
copy of the exercise files, which corrects this issue for you. For a
more in-depth explanation of the difference between bindValue() and
bindParam(), check out the "Binding input and output values" video (http://www.lynda.com/PHP-
Q: Why can't I access the Lake Pend Orielle site (http://lpo.dt.navy.mil)?
A: The Lake Pend Orielle site is not accessible in some geographical areas. We have contacted the owner of the server to try to resolve this issue.
Q: I am unable to access the Lake Pend Oreille data from outside the U.S.
A: A static copy of this data is provided here for lynda.com members outside of the U.S
Related Courses
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Advanced PHP: Debugging Techniques
with Jon Peck1h 29m Intermediate -
PHP: Exporting Data to Files
with David Powers3h 42m Intermediate -
Code Clinic: Ruby
with Kevin Skoglund5h 42m Intermediate
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Introduction
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Welcome1m 14s
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Using the exercise files1m 56s
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Problem One: Statistical Analysis
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Overview of my solution3m 22s
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Setting up the database4m 55s
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Processing the full-year records10m 49s
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Processing individual days6m 54s
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Keeping the data up to date4m 27s
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Creating a web service6m 21s
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Getting the required data6m 50s
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Problem Two: Image Analysis
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Identify the image subset3m 14s
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Overview of my solution3m 19s
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Setting up the files2m 43s
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Generating the thumbnails7m 49s
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Finding the cropped images7m 13s
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Problem Three: Eight Queens
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Overview of my solution3m 48s
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Rotating the chessboard4m 59s
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Problem Four: Accessing Peripherals
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Overview of my solution2m 1s
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Using the Web Audio API2m 47s
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Creating the tone generator7m 39s
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Problem Five: Recursion and Directories
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Overview of my solution3m 24s
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Finding the images5m 30s
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Extracting XMP metadata6m 22s
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Problem Six: Building the Web
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Building the web1m 47s
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Overview of my solution1m 50s
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Video: Finding all possible combinations