Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>I would favor a recursive solution. You have some list of denominations, if the smallest one can evenly divide any remaining currency amount, this should work fine.</p> <p>Basically, you move from largest to smallest denominations.<br> Recursively,</p> <ol> <li>You have a current total to fill, and a largest denomination (with more than 1 left). If there is only 1 denomination left, there is only one way to fill the total. You can use 0 to k copies of your current denomination such that k * cur denomination &lt;= total.</li> <li>For 0 to k, call the function with the modified total and new largest denomination.</li> <li>Add up the results from 0 to k. That's how many ways you can fill your total from the current denomination on down. Return this number.</li> </ol> <p>Here's my python version of your stated problem, for 200 cents. I get 1463 ways. This version prints all the combinations and the final count total.</p> <pre><code>#!/usr/bin/python # find the number of ways to reach a total with the given number of combinations cents = 200 denominations = [25, 10, 5, 1] names = {25: "quarter(s)", 10: "dime(s)", 5 : "nickel(s)", 1 : "pennies"} def count_combs(left, i, comb, add): if add: comb.append(add) if left == 0 or (i+1) == len(denominations): if (i+1) == len(denominations) and left &gt; 0: comb.append( (left, denominations[i]) ) i += 1 while i &lt; len(denominations): comb.append( (0, denominations[i]) ) i += 1 print " ".join("%d %s" % (n,names[c]) for (n,c) in comb) return 1 cur = denominations[i] return sum(count_combs(left-x*cur, i+1, comb[:], (x,cur)) for x in range(0, int(left/cur)+1)) print count_combs(cents, 0, [], None) </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POHow to find all combinations of coins when given some dollar value
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USleif
    1. USleif
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COHaven't ran it, but by going through your logic, it makes sense :)
      singulars
      1. PO
      1. UScodingbear
    2. COYou can replace the last two lines of the function with "return sum(count_combs(...) for ...)" - that way the list doesn't get materialized at all. :)
      singulars
      1. PO
      1. USNick Johnson
    3. COThanks for the tip. I'm always interested in ways to tighten up code.
      singulars
      1. PO
      1. USleif
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload