I don't really understand what you are having trouble with. Be more clear about that. If you don't know how to determine the number of asterisks a salesperson should get, just set up a simple ratio:
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int maxAsterisks = 50;
int numAsterisks[100];
//do bubble sort
numAsterisks[0] = maxAsterisks;
for(int i = 1; i < 100; i++)
{
numAsterisks[i] = (int)(sales[i]/sales[0]*maxAsterisks);
}