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POC++ Selection Sort on Array of Structures
 

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    <p>I am working through a C++ book, and I am a little stuck on one of the challenge questions. I'm working on learning about pointers, and in this particular problem I need to sort an array of structures (using pointers) with a string of a student's name and a double of their score. After the sort, the structure's data members still need to match up, obviously (i.e. the right name's still need to be with their scores).</p> <p>This is where my problem lies. So far, I have the sort properly arranging the scores in ascending order, but the names get all jumbled up. I haven't been able to figure out why, partly because I am still working to fully understand pointers and how to use them. I can do a bubble sort correctly, keeping the names with their scores, but not the selection sort. Any help would be greatly appreciated.</p> <p>Here is the function I have for the selection sort:</p> <pre><code>void selection_sort(Student *ptr, int size) // selection sort - having some problems { int start, min_index, min_value; for (start = 0; start &lt; (size - 1); start++) { min_index = start; min_value = (ptr+start)-&gt;score; for (int index = start+1; index &lt; size; index++) { if ( (ptr+index)-&gt;score &lt; min_value) { min_value = (ptr+index)-&gt;score; min_index = index; } } // the following line is where, i think, the problem is, but i haven't // been able to figure out the solution, despite trying numerous approaches *(ptr+min_index) = *(ptr+start); (ptr+start)-&gt;score = min_value; } } </code></pre> <p>So that is what I have. I'm not great with sorting algorithms yet either, and this is all pretty new to me, so I hope it's not horribly messed up. If anyone knowledgeable in these areas could point me in the right direction, that would be awesome.</p>
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    1. COIn C++ one does not pass pointers and sizes as arguments to functions. Instead, one uses a standard container (such as a vector) and passes a begin and an end iterator.
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