CODEWITHSUNDEEP
javamatrixvector
Blanaru Daniel
Blanaru Daniel

Reputation: 11

cant get a matrix from vector

I'm new to Android Studio and I have been trying to get a matrix from a vector, modify it and put it back but when I increment the matrix, the vector change the automatically its value from where I took the matrix... and I can't figure out why? Here is my code :

Vector<int[][]> internalProces(int prNo, Vector<int[][]> vector)
    {
        int[][] matrix =new int[processNo][processNo];
        matrix=vector.lastElement();
        matrix[prNo][prNo]++;
        vector.add(matrix);
        return vector;
 }
    public void test(){
    Vector<int[][]> vector=new Vector<>();
    VectorClk vectorClock = new VectorClk(3);
    vector=vectorClock.initialize(vector);
    vector=vectorClock.internalProces(1,vector);        
}

Thanks!

DEBUGER

Upvotes: 1

Views: 35

Answers (1)

Mạnh Quyết Nguyễn
Mạnh Quyết Nguyễn

Reputation: 18235

In matrix=vector.lastElement(); step, you must do a deep copy instead of copy reference:

(from your code I assume that your vector consist of 2-d array with size processNo x processNo and processNo > prNo)

int[][] vectorElement = v.lastElement();
for (int i = 0; i< vectorElement.length; i++) {
    System.arraycopy(vectorElement[i], 0, matrix[i], 0, vectorElement[i].length);
}

Upvotes: 1

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