如何在C ++中将双指针矩阵转换为单指针向量？

Question

I have an double pointer matrix that i want to convert to a single pointer vector in c++. here is the code:

int main(){
    int AA[2][2] = {1,2,3,4};
    int i,j,k;
    int kolB,barB;
    int **BB,**CC;
    int *A,*B,*C;

    BB = new int*[barB];
    CC = new int*[2];

    for(i=0;i<kolB;i++){
        BB[i] = new int[kolB];
        CC[i] = new int[kolB];
    }

    free(BB);
    free(CC);

    return 0;
}

i want to insert **AA value to *A, can you guys help me with this?

Answer 1

If i understand your question correctly, you want to access each element in the double pointer array and put it in a single pointer array like this:

//assuming kolB,barB,**BB have been initialized
B=new int[kolB*barB];//create a one dimensional integer array to be pointed to by int* B

//then copy the value from double pointer array to this new one dimensional array
for(int i=0;i<barB;i++)
   for(int j=0;j<kolB;j++)
       B[(i*barB)+j]=BB[i][j];//you need to copy each value

If you are thinking of doing B=(int*)BB; and access it like B[i] , that will not work,so don't. BTW there are some interesting comments at the comment section of your question, you may want to take a look at them and improve your code.