📄 12exerc.html
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<h3>Exercises</h3>
<p>You may compare your solutions with my <a href="solutions2.html">solutions</a>.
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<li>Add method <var>Top ()</var> that returns the value from the top of the stack without changing its state. Add method Count that returns the count of elements on the stack.
<li>Modify the main function so that one of the stack contracts is violated. See what happens when you run the program with the assertions turned on.
<li>Modify the stack so that it becomes <var>CharStack</var>--the stack of characters. Use it to invert strings by pushing all the characters of a string, and then popping and printing them one by one.
<li>Design the abstract data type <var>Queue</var> of doubles with methods <var>Put</var> and <var>Get</var> and the FIFO (First-In-First-Out) behavior. Implement it using an array and two indices: the put index, and the get index that trails the put index. The contract of this particular queue reads: The <var>Put</var> method shall never be called more than <var>maxPuts</var> times during the lifetime of the <var>Queue</var>. Thou shalt not <var>Get</var> when the <var>Queue</var> is empty.
<li>Design and implement the <var>DblArray</var> data type with the methods:
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<pre>void Set (int i, double val)</pre>
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and
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<pre>double Get (int i) const</pre>
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to set and get the values of the particular cells in the array. Add one more method
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<pre>bool IsSet (int i) const </pre>
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that returns <var>false</var> if the cell has never been set before and <var>true</var> otherwise. The contract is that no <var>Sets</var> or <var>Gets</var> shall be done with the index greater than <var>maxCells</var>; that one shall never try to get a value that hasn't been set before, and that one shouldn't try set a value that has already been set before (write once-read many times array). The array may store any values of the type <var>double</var>.
<p>Hint: if you want to negate a Boolean resut, put an exclamation mark in front of it. For instance
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<pre>!IsSet (i)</pre>
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is <var>true</var> when the cell is <i>not</i> set and <var>false</var> when it is.
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