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我需要調用GetNewItem
函數百萬次;Java - 結構交集ArrayList
Items XY = GetNewItem(X, Y);
Items XYZ = GetNewItem(XY, Z);
Items XZ = GetNewItem(X, Z);
Items YZ = GetNewItem(Y, Z);
該功能的目的是ArrayList的結構的 1-發現路口之間即
ArrayList<Records> RecordLists
2和它也計算爲新的ArrayList的概率,這是我的代碼:
class Records {
public int RecordId;
public double Prob;
}
class Items {
public ArrayList<Integer> itemId;
public ArrayList<Records> RecordLists;
public double ItemProb = 0.0;
};
private ArrayList<Records> Intersection(ArrayList<Records> list1, ArrayList<Records> list2) {
ArrayList<Records> Result = new ArrayList<>();
int i = 0, j = 0;
while (i < list1.size() && j < list2.size()) {
if (list1.get(i).RecordId== (list2.get(j).RecordId)) {
Records RecordDetails= new Records();
RecordDetails.RecordId= list1.get(i).RecordId;
RecordDetails.Prob+= 1;
Result.add(RecordDetails);
i++;
j++;
} else if (list1.get(i).RecordId < list2.get(j).RecordId) {
i++;
} else if (list1.get(i).RecordId > list2.get(j).RecordId) {
j++;
}
}
return Result;
}
public Items GetNewItem(Items item1, Items item2) {
Items NewItem = new Items();
ArrayList<Integer> newItemId = new ArrayList<>();
newItemId.addAll(item1.itemId);
newItemId.addAll(item2.itemId);
NewItem.itemId = newItemId;
NewItem.RecordLists= Intersection(item1.RecordLists,item2.RecordLists);
NewItem.ItemProb = getProb(NewItem.RecordLists);
return NewItem ;
}
private double getProb(ArrayList<Records> RProb) {
double IProb = 0.0;
for (int i = 0; i < RProb.size(); i++) {
IProb += RProb.get(i).Prob;
}
return IProb ;
}
對於此代碼我得到'內存不足錯誤'
我不知道如何節省內存和時間,我想這個解決方案: java.lang.OutOfMemoryError: Java heap space with NetBeans
但我的電腦沒有凍結。我不知道我還有什麼要做。
爲什麼你需要調用函數一百萬次? –