Coins

[mia023]

Hi i have an assignment that i don't understand and need help in.

Write a program that reads in a command line integer N(number of pennies) and prints out the best way(fewest number of coins) to make change using US coins (quarters, dimes, nickels and pennies only). Your algorithm should dispense as many quarters as possible, then dimes, then nickels, and finally pennies.

[JosAH]

Hi i have an assignment that i don't understand and need help in.

Write a program that reads in a command line integer N(number of pennies) and prints out the best way(fewest number of coins) to make change using US coins (quarters, dimes, nickels and pennies only). Your algorithm should dispense as many quarters as possible, then dimes, then nickels, and finally pennies.

Here's a little hint: suppose you've got 81 pennies; watch this:

81/25 == 3 (quarters)
81%25 == 6 (rest of the change)

etc. etc.

kind regards,

Jos

[mia023]

why did you do 81%25 and how can i get the rest

[JosAH]

why did you do 81%25 and how can i get the rest

The % is operator is Java's (and C and C++'s) modulo operator. 81%25 == 6
because the rest is 6 when you divide 81 by 25.

kind regards,

Jos

[mia023]

should i use nested loops or if statements

[Ganon11]

I don't think you'll need either - just repeat Jos' set of commands for quarters, dimes, and nickels, and whatever is left is pennies.

[mia023]

this is my code but i think it is wrong


public class Coin{
public static void main(String[]args){
int N=Integer.parseInt(args[0]);

int q=N%25;
int d=N%10;
int n=N%5;

int p=q+d+n;

System.out.println(N/25+" quarters");
System.out.println(N/10+" dimes");
System.out.println(N/5+" nickels");
System.out.println(p+" pennies");
}
}

[mia023]

sorry i send the code 2 times it was by mistake

[JosAH]

sorry i send the code 2 times it was by mistake

No need to worry, I removed one of them; and indeed your code is completely wrong.
Back to the example again: for 81 pennies you can fit 81/25 == 3 quarters and
you have 81%25 == 6 pennies left. Now generalize this and don't sprinkle in
the / and % operators where they don't make sense. Do your math.

kind regards,

Jos

[mia023]

No need to worry, I removed one of them; and indeed your code is completely wrong.
Back to the example again: for 81 pennies you can fit 81/25 == 3 quarters and
you have 81%25 == 6 pennies left. Now generalize this and don't sprinkle in
the / and % operators where they don't make sense. Do your math.

kind regards,

Jos

should i loop them and for example generalize the formula by N%num where N is the number of pennies and num is how many pennies are worth in dimes,nickels and quarters

[r035198x]

should i loop them and for example generalize the formula by N%num where N is the number of pennies and num is how many pennies are worth in dimes,nickels and quarters

Indeed you should generalize it.

[mia023]

Indeed you should generalize it.

Can you please tell me the conversions(pennies to quarters,etc....) and tell me what is wrong with the code above.

[r035198x]

Can you please tell me the conversions(pennies to quarters,etc....) and tell me what is wrong with the code above.

I don't know what you mean by conversions (pennies to quarters ...), I've never even seen any of them ...

What you need to do is have your algorithm (pseudo code) down.
Store the denominations in, say an array. Biggest coing on position 0, second biggest on position 1, e.t.c and smallest coin on last posistion in the array.
The algorithm should be very easy to construct from there using the greedy algorithm.