/* Challenge: CASH BACK (re-posted) A certain Sololearner had already posted this challenge and it seems to have been removed since. From what I am aware of I was the only Sololearner to have answered the challenge, and I am now re-posting this challenge because I think other's should take a shot at it. So, the challenge is to write a program that returns the change given in return for a purchase. For example, if $100.00 is given for a purchase costing $4.12, then, depending on the currency (which can be any currency), the change, in order of largest to lowest denominations of the chosen currency (in this case it is a fictional, general dollar currency) for the convenience of the buyer to not have to carry around any more small change than utterly necessary is returned to the purchaser: $50.00 $20.00 $20.00 $5.00 $0.50 $0.20 $0.10 $0.05 $0.02 $0.01 Total change: $95.88 The challenge is to produce a program that receives a value as input representing the amount of money given to the seller, deducts an amount for representing the price of the purchase, and then generates output such as above. An example program written by myself: https://code.sololearn.com/czTC0jrt3HKV/#py # The purchase amount (does not round) SPEND = 4.12 # List of all denominations in currency DENOM = [1000, 500, 100, 50, 20, 10, 5, 2, 1, 0.5, 0.2, 0.1, 0.05, 0.02, 0.01] def change(m): """Recursive function for calculating the change given from a purchase""" if m < sorted(DENOM)[0]: return m if m < 0 else 0 c = max([c for c in DENOM if c <= m]) print("${:.2f}".format(c)) return c + change(round(m - c, 2)) try: print("\nTotal change: ${:.2f}".format(change(float(input()) - SPEND))) except: print("Input value not valid, only money") */ #include #include #include using namespace std; // global data => filestream shoud be implemented const float denominations[] = { 50.00, 20.00, 10.00, 5.00, 2.00, 1.00, 0.50, 0.25, 0.10, 0.05, 0.01 }; const int denominationsNo = sizeof ( ::denominations ) / sizeof ( float ); auto precision = [] ( float x ) -> int { return ( x + 0.001 ) * 100 ;}; // handle float unprecisions void change( float purchase , float given ) { int totalChangePrecision = precision( given ) - precision( purchase ); cout<< "Change: " << totalChangePrecision / 100.0 << "$" << endl; while ( 0 < totalChangePrecision ) { for ( int i = 0 ; i < ::denominationsNo ; i++ ){ if ( precision( ::denominations[ i ] ) <= totalChangePrecision ){ cout<< ::denominations[ i ] << "$" << endl; totalChangePrecision -= precision( ::denominations[ i ] ); break ; } } } } int main() { srand( time( 0 ) ); float purchase = ( rand() % 10000 ) / 100.0; float given = 100; cin>> purchase ; cin>> given ; cout<< "Purchase: "<< purchase<< "$"<< endl; cout<< "Given: "<< given<< "$"<< endl; cout<< endl; change( purchase, given ); cout<<"\nend\n"; return 0; }