有人可以帮助我解决我的C ++代码

Question

Hello i'm new in c++ and i want to convert my code from pascal to c++ so this is my try :

void decomp(int x, int *t[], int *l){
int p = 2;
int l = 0;

do{
if (x % p == 0){
x = x / p;
t[l] = p;
l += 1;     
}
else { p += 1; }
} while (x != 1);

}

and this is the correct function is pascal if someone need it to understand :

procedure decomp(x:integer; var t : tab; var l : integer);
var
p : integer;
begin
l : = 0;
p: = 2;
repeat
if (x mod p = 0) then
begin
x : = x div p;
l: = l + 1;
t[l]: = p;
end
else
p: = p + 1;
until(x = 1);
end;

the issue is the compiler give me an error message : t[l]=p under li have this error : expression must have integral or unscoped enum type and under = i have this error : a value of type int cannot be assigned to an entity of type int*

PS the function need to return an array and his size ( var t :tab ; var l :integer)

Answer 1

You're shadowing the parameter l with a local variable l . Replace the int l = 0; with just *l = 0; . You'll have to dereference l wherever you use it.

Better yet, pass l by reference instead of by a pointer. This will be more similar to var l: integer in the Pascal code.

void decomp(int x, int *t[], int &l)

Then you won't have to dereference l as a pointer everywhere.

Also, t is an array of pointers. You're trying to assign an integer to a pointer. I'm not certain how to solve this with the code you have. Perhaps it doesn't need to be an array of pointers:

void decomp(int x, int t[], int &l)
{
    int p = 2;
    l = 0;

    do
    {
        if (x % p == 0)
        {
            x = x / p;
            t[l] = p;
            l += 1;
        }
        else
        {
            p += 1;
        }
    } while (x != 1);
}

Answer 2

This:

int *t[]

is array of pointers to int, you need arrays of int. So when you try to assign t[l]=p you assigning int to int * hence the error. and for l you need reference, not pointer, so you code could be like this:

void decomp(int x, int t[], int &l){
    int p = 2;
    l = 0;

    do{
        if (x % p == 0){
           x /= p;
           t[l++] = p;
        }
        else { ++p; }
    } while (x != 1);
}