C - “使用结构指针时出错”

Question

I have a function to which I send elements of an array structure, but, for some reason, an error constantly comes out

typedef struct student{
    char *fullName;
    char groupNumber[8];
    float GPA;
}student;
int cmpName(student* p1, student* p2){
    printf("%s\n",p1->fullName);
    return (strcmp(p1->fullName,p2->fullName));
}

void gnomeSort(student **mass,int size,int (*cmpFunc)(student *p1, student *p2)){
        int index = 0;
        while (index < size){
            if (index == 0)
                index++;
            if (cmpFunc(mass[index],mass[index-1]))
                index++;
            else{
                student *tmp;
                tmp = mass[index-1];
                mass[index-1] = mass[index];
                mass[index] = tmp;
                index--;
            }

        }
}

I understand that the problem is most likely in the pointers, but I do not know how to solve it

Answer 1

try not to make function in the arguments

void gnomeSort(student **mass,int size,int (*cmpFunc)(student *p1, student *p2))

replace int (*cmpFunc)(student *p1, student *p2) with int param and execute the function cmpName() independently, then call gnomeSort()