Working with Pointers

In your class directory, create a new directory called Pointers. In the Pointers directory, write a program for each of the exercises below.

The goal of this exercise is to write a function swap that swaps two integer values. Our first attempt, outlined below, did not work.

    void swap(int x, int y)
    {
        int tmp = x; 
        x = y; 
        y = t;
    }

    int main()
    {
        int num1 = 111, num2 = 222;

        swap(num1, num2);
        printf("\n num1=[%d], num2=[%d]\n", num1, num2);
    }

Use pointers to fix the code (try for a minimal number of changes).

Assume now that the two integer values are stored into an array. Fill in the missing code below to swap the two array elements.

 
    void swap2(____________)
    {
        int tmp    = _________; 
        __________ = _________; 
        __________ = _________; 
    }

    int main()
    {
        int num[2] = {111, 222};

        swap2(___________);
        printf("num[0]=[%d], num[1]=[%d]\n", num[0], num[1]);
    }

The output should be

    num[0] = 222, num[1] = 111