4.6: Merging Decks
- Page ID
- 15296
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The next helper method we need is merge
, which takes two sorted subdecks and returns a new deck containing all cards from both decks, in order. Here’s what the algorithm looks like in pseudocode, assuming the subdecks are named d1
and d2
:
public static Deck merge(Deck d1, Deck d2) { // create a new deck big enough for all the cards // use the index i to keep track of where we are at in // the first deck, and the index j for the second deck int i = 0; int j = 0; // the index k traverses the result deck for (int k = 0; k < result.cards.length; k++) { // if d1 is empty, d2 wins // if d2 is empty, d1 wins // otherwise, compare the two cards // add the winner to the new deck at position k // increment either i or j } // return the new deck }
One of the exercises at the end of the chapter asks you to implement merge
.