Filling Java 2D array input

Question

I am trying to get user input in a 2D array. I would like not to use java.util.Arrays if possible.

User input looks like this, the first integer being the number, the second the index of the integer.

3 3
1 2
3 2

This is what I get

[3,3,1][2,3,2][][][][]

This is what I would like to get

[][1,3][3][][][]

---

int x = sc.nextInt();
int array[][] = new int[6][x];

for (int i = 0; i < x; i++ ){
    for (int j = 0; j < x; j++) {
        array[i][j] = sc.nextInt();
    }   
}

System.out.println(Arrays.deepToString(array));

Answer 1

I expect you mean format:

number index_to_add

This is not simple, because you don't know, how many numbers will be in array at start.

I would use a collection like ArrayList etc.

If you really want to use just arrays, you have to have a top limit.

ArrayList version:

ArrayList<Integer>[] list = new ArrayList<Integer>[6];

//init
for(int i=0;i<list.length;i++){
    list[i] = new ArrayList<Integer>();
}

//fill
while(sc.hasNextInt()){
    int number = sc.nextInt();
    if(sc.hasNextInt()){
        int index_to_add = sc.nextInt();
        list[index_to_add].add(number);
    }else{
        break;
    }
}

Note: code not tested;