在 C++ 中使用 STD::List

Question

well I am making a Sudoku puzzle, and I am trying to compare whether a number can go in a row because of the number already existing in a row, and im very new to c++ and well im okay at c# and I have this

for (int i= 0; i< fifth.size(); i++)
        {
            for (int c= 0; c<9; c++)
            {
                listConnectordown1[c] == fifth[i];


 //then the number can not go in here because it already exists in the row but not the
block
            }
        }

as you can see im getting the error at listConnectordown1[c] == fifth[i]; because of lack of knowledge with c++ could anybody help me so I can compare them correctly?

the error is

4   IntelliSense: no operator "[]" matches these operands
        operand types are: std::list<int, std::allocator<int>> [ int ]  j:\08227 acw\ACW\Sudoku\Sudoku\main.cpp 152

I have now changed to a vector given advice, now I don't know how to remove a certain value when it needs to be removed for example

int possbileChecks[] = {1,2,3,4,5,6,7,8,9};
            std::vector<int> fifth (possbileChecks, possbileChecks + sizeof(possbileChecks) / sizeof(int) );
        for (int i = 0; i < 3; i++) {
        for (int j = 0; j < 3; j++) {
            PossibleChecks = Block1[i][j];

            if (!PossibleChecks == 0)
            {
            PossibleValuesInsideBlock[count] = PossibleChecks;
            //ValueRemove = count-1;
            possiblValuesCount = PossibleChecks-1;
            fifth.Remove(PossibleChecks);
            possiblValuesCount=0;

            count = count++;
            }   

        }
        }

Answer 1

std::list doesn't provide index access functionality. It is implemented as a doubly linked list, so if you want to randomly access elements in the list it's probably not the right choice for you. What you probably want is std::vector :

std::vector<int> v(1);
v[0] = 0;

if(v[0] == 0)...
    ... // etc

If you want to stick to the list you should use iterator functions, like begin and advance .

Answer 2

std::List in c++ is not the same as a list in C#, you aren't able to loop through list like this.

to iterate through std::list you will have to use an iterator(std::list::Iterator):

    list<int>::const_iterator it;
    for(it = list1.begin();it != list1.end();it++)
    {
        for(list<int>::const_iterator c = list1.begin();c != list1.end();c++)
        {
            c == it;
        }
    }

or use a range based for loop:

    //Range based for loop
    for(int i :list1)
    {
        for(int c : list2)
        {
            i == c;
        }
    }

or just use a std::vector instead of std::list and your code will work