使用结构指针实现气泡排序

Question

The structure is

   struct student
{
    char name[10];
    int roll;
    int percent;
};

struct student s[5];
struct student *p;

The above declaration is Global. And this is my Bubble Sort function.

    void sort(int n)
    {
    int i,j,k;
    struct student temp;
    for(i=0;i<=(n-2);i++)
    {
        for(j=0;j<(n-i-1);j++){
        if((p+j)->percent>(p+j+1)->percent){
//Define the temp variable of Structure type
        temp=*(p+j);//Interchange s[j] and s[j+1]
        *(p+j)=*(p+j+1);
        *(p+j)=temp;
            }
        }
    }

I want to avoid using the dot operator to access elements of the structure The temp variable for swapping has been declared of the structure type. This Bubble Sort function is not working. These are the lines where I think I messed up. Please point out the mistake.

if((p+j)->percent>(p+j+1)->percent){
            temp=*(p+j);//Interchange s[j] and s[j+1]
            *(p+j)=*(p+j+1);
            *(p+j)=temp;

Answer 1

The swap logic is wrong, first you set temp to *(p+j), then you set *(p+j) to *(p+j+1) but then you make a mistake and just write on *(p+j) again. I believe changing

*(p+j)=temp;

to

*(p+j+1)=temp;

should fix it

Answer 2

One obvious problem is your exchange logic:

if((p+j)->percent>(p+j+1)->percent){
    temp=*(p+j);//Interchange s[j] and s[j+1]
    *(p+j)=*(p+j+1);
    *(p+j)=temp;
}

The final assignment is to the wrong element, and is doing nothing more than reversing the previous assignment. Change it to:

if((p+j)->percent>(p+j+1)->percent){
    temp=*(p+j);//Interchange s[j] and s[j+1]
    *(p+j)=*(p+j+1);
    *(p+j+1)=temp;
}