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java 笛卡爾積 數組,帶有Java集合的笛卡爾積

java 笛卡爾積 數組,帶有Java集合的笛卡爾積

I am trying to create a cartesian product method in java that accepts sets as arguments and returns a set pair. The code I have coverts the argumented sets to arrays and then does the cartesian product but i can't add it back to the set pair that i want to return. Is there an easier way to do this? Thanks in advance.

public static Set> cartesianProduct(Set a, Set b) {

Set> product = new HashSet>();

String[] arrayA = new String[100];

String[] arrayB= new String[100];

a.toArray(arrayA);

b.toArray(arrayB);

for(int i = 0; i < a.size(); i++){

for(int j = 0; j < b.size(); j++){

product.add(arrayA[i],arrayB[j]);

}

}

return product;

}

解決方案

this looks simpler,

public static Set> cartesianProduct(Set a, Set b) {

Set> product = new HashSet>();

for(S s : a) {

for(T t : b) {

product.add(new ImmutablePair(s,t));

}

}

return product;

}