78. Struct Padding

#include <stdio.h>

typedef struct {
    char a;
    int b;
    short c;
} MyStruct;

void print_offsets() {
    MyStruct ms;

    printf("Offset of a: %u\n", (char*)&(ms.a) - (char*)&(ms.a));
    printf("Offset of b: %u\n", (char*)&(ms.b) - (char*)&(ms.a));
    printf("Offset of c: %u\n", (char*)&(ms.c) - (char*)&(ms.a));
    printf("Size: %u", sizeof(ms));
}

int main() {
    print_offsets();
    return 0;
}

Basically, pointer arithmetic returns a value based on the size of the data type.

So, you should cast to char* to calculate offsets in bytes