cs1101x: programming methodology recitation 6 arrays i

CS1101X: Programming Methodology

Recitation 6 Arrays I

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Task 1: Learning-by-mistake

To be given out at the recitation.

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Task 2: isSorted

A program IsSortedArray.java to test whether a list of integers in sorted in non-decreasing order. The method isSorted() returns true if the array is sorted; it returns false otherwise.

Based on what we have discussed for task 1, can you write the isSorted() method?

3 5 5 7 18 21 true

1 3 4 7 6 9 11 false

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Task 3: Second largest

Given a list of integers, determine the second largest value in the list. (Assuming that the list contains at least 2 values.)

10 3 7 15 11 21 15

5 8 7 9 2 8 1 3 8

12 7 9 12 10 3 12

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Task 4: Pascal’s Triangle (1/3)

Blaise Pascal was a scientist, mathematician par excellence who lived in the 17th century. Some of his mathematical work was fundamental to the theory of probability. There is also a programming language named after him (though in no real sense related to him). More of him in this website (for those who are interested): http://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Pascal.html

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Task 4: Pascal’s Triangle (2/3)

In this problem, you are asked to generate Pascal's Triangle. Pascal's Triangle is useful in many areas from probability to polynomials to setting programming questions. It is a triangle of integers with 1 on top and down the sides. Any number in the interior equals the sum of the two numbers above it. For example, here are the first 5 rows of the triangle. 1

1 11 2 1

1 3 3 1

1 4 6 4 1

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Task 4: Pascal’s Triangle (3/3)

Write a program to generate a Pascal’s Triangle as shown. It should be observed that the next row of the Pascal’s triangle can be generated from the previous row. Thus, using an array to store the values of the previous rows seems appropriate.

11 11 2 11 3 3 11 4 6 4 11 5 10 10 5 1

Output for n (number of rows) = 6.

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To be continued…

More problems on arrays (including array of objects) at the next recitation.

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End of Recitation #6