CODEWITHSUNDEEP
cfunctionsortingpointersbubble-sort
Salman Mukadam
Salman Mukadam

Reputation: 15

How do i sort an array in a function using pointer notation and the bubble sort algorithm in C

I'm trying to sort 6 numbers input by the user using a bubble sort algorithm. My program has to be modular so I've written the program as a separate function but I keep getting two errors and I have no idea how to correct them.

Error 1. Lvalue required in function sort_Nums(int *)

Error 2. Expression syntax in function sort_Nums(int *)

Here's my code: 

void sort_Nums(int*picked_nums)
{
    int i,step,temp;

    for(step=0; step<SIZE-1; ++step)
        for(i=0; i<SIZE-step-1; ++i)
        {
            if(*(picked_nums+i) > *(picked_nums+i)+1)
            {
                temp=*(picked_nums+i);
                *(picked_nums+i) = *(picked_nums+i)+1;
                *(picked_nums+i)+1 = temp;
            }
        }

        printf("The numbers you chose in order are:\n");
        for(i=0; i=<SIZE; ++i)
        {
            printf("%d\n", *(picked_nums+i));
        }   

        printf("Press any key to return to main menu");
        getchar();
    }

Thanks in advance and I am sorry if this is a stupid question and its just a syntax error or something but I've been coding for 9 hours almost now and this assignment is due tomorrow so this is a kind of last resort thing.

Upvotes: 0

Views: 119

Answers (2)

Janne Tuukkanen
Janne Tuukkanen

Reputation: 1660

Here you are adding 1 to the value, not to the pointer, and the second line causes the Lvalue error:

*(picked_nums+i)=*(picked_nums+i)+1;
*(picked_nums+i)+1=temp;

Corrected code would be like this:

*(picked_nums+i)=*(picked_nums+i+1);
*(picked_nums+i+1)=temp;

Upvotes: 0

Abhijit Pritam Dutta
Abhijit Pritam Dutta

Reputation: 5591

Hi your if condition if(*(picked_nums+i)>*(picked_nums+i)+1) is wrong it should be if(*(picked_nums+i)>*(picked_nums+i+1)). As per bubble short logic you need to compare with next element in the array. Like

if (arr[1] > arr[2] )

and you are doing 

if (arr[1] > arr[1] + 1 ) which is wrong.

Suppose arr[1] = 4 and arr[2]=3

with the below if condition it should swipe

if (arr[1] > arr[1+1] ) because it is if (4 > 3) which is true

But your if condition is doing like below

if (arr[1] > arr[1] + 1) which is equal to if (4 > 3+1 ) which is false

Upvotes: 1

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