PhoneCall

/*
  Phone Call:
  
  Some phone usage rate may be described as follows:

    -first minute of a talk costs "min1" cents,
    -each minute from the 2nd up to 10th (inclusive) costs "min2_10" cents
    -each minute after 10th costs "min11" cents.
    
  You have S cents and you want to know how many minutes as maximum can you 
  talk.

  for example:
  
  min1 = 3 , min2_10 = 1 , min11 = 2 and S = 20
  phoneCall(min1, min2_10, min11, S) = 14

  Since you have 20 cents 20-3 of the minute one is 17
  17-9 of minutes 1 to 10 is 8 and you have talked 10 minutes
  so you can talk another 4 because 8 - 2*4 = 0 finally you can
  talk 14 minutes as total.
*/

int phoneCall(int min1, int min2_10, int min11, int S) 
{
   int min = 0;
    
   if(S >= min1)
	    {	    	
	        min++;
	        S-=min1;

	        if(S > min2_10)
	        {
	            for( min=2 ; min <= 10;min++)
	            {
	                if(S<=0)
	                {
	                    break;
	                }
	                S-=min2_10;
	            }
	            
	            while(S>0)
	            {
	                min++;
	                S-=min11;
	            }
	            min--;
	            
	            if(S<0)
	            {
	            	min--;
	            }
	        }
	    }
    return min;
}