我不明白为什么我的程序在数组的索引中要求指针

Question

I am writing a code to find the intersection of 2 arrays. With my i and j iterators, the IDE is asking me to convert them to pointers or something. I'm specifically getting a pointer-to-object error.

Also I can't really wrap my head around when and how to use pointers. I know what they are (kind of) but I don't understand when to use them.

void arrIntersect(int fArr, int sArr, int fArrElem, int sArrElem)
{
    int i, j, k;

    int largeArrElem = (fArrElem > sArrElem)?fArrElem:sArrElem;
    int unionArr[largeArrElem];

    for (i = 0; i < largeArrElem; i++)
    {
        for (j = 0; j < largeArrElem; j++)
        {
            if (fArr[i] == sArr[j]) //Here the i and j say pointer to object//
            {
                for (k = 0; k < largeArrElem; k++)
                {
                    unionArr[k] = fArr[i]; //Here the i says pointer to object//
                }
                break;
            }
            break;
        }

    }

    for (k = 0; k < largeArrElem; k++)
    {
        printf("%d, ", unionArr[k]);
    }

}

Answer 1

Hi your intersection function is not right.You must decrise the size of largArrElem and also you have to decrise the size of j.Now for your problem with the arrays did you try to to create them dynamicaly with malloc?Also if you did that i thing you must add " * " in parametres like:

void arrIntersect(int *fArr, int *sArr, int fArrElem, int sArrElem)

Answer 2

Use it, there will be no error -

void arrIntersect(int fArr[], int sArr[], int fArrElem, int sArrElem)