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Differential Directory, indexing method 3 Weeks Ago by xrjf … in record 1 is not S, so we follow the pointer to record 2. If it matches, we insert a new… Re: Differential Directory, indexing method 3 Weeks Ago by rproffitt DiDi appears to be some China based UBER service but then again I can't find a question or much else to discuss here. Re: Differential Directory, indexing method 3 Weeks Ago by xrjf About DiDi DiDi (Differential Directory) was originally developed as part of my thesis project in the early 1990s. The name bears no relation to the more recent Chinese ride-sharing company. At the time, DiDi was a novel approach within its academic context, but a change in legislation unfortunately led to the closure of the school and the … Re: Differential Directory, indexing method 3 Weeks Ago by xrjf For example, as Donald Knuth points out in The Art of Computer Programming, the theoretical lower bound for comparison-based sorting algorithms is K × log₂(N). I developed a very simple method that matches this performance. However, DiDi goes far beyond: its performance is proportional to K × (maximum key length), regardless of the number of … Re: Differential Directory, indexing method 3 Weeks Ago by xrjf As an illustration, consider the theoretical lower bound for comparison-based sorting, as stated by Donald Knuth in The Art of Computer Programming: K × log₂(N). I developed a simple method that matches this limit. For example, to sort the list {2, 5, 7, 1, 4, 3, 8, 6}: Sort pairs: (2, 5) → [1] (1, 7) → [2] (3, 4) → [3] (6, 8) → [4] Merge… Re: Differential Directory, indexing method 3 Weeks Ago by xrjf "Just to clarify a previous mistake: the efficiency should be K × N × log₂(N), not K × log₂(N) as I initially wrote." Re: Differential Directory, indexing method 2 Weeks Ago by xrjf I've just made an update because some records weren't being added properly. The issue was that the form didn't take into account that the register field (in the call to DiDi) is passed by reference. Re: Differential Directory, indexing method 1 Week Ago by xrjf Just a quick update for anyone interested: I have revisited and significantly improved the code, aiming for a more professional structure and better performance. The updated version avoids freezing the UI during long operations and follows more robust programming practices. If you’d like to see DiDi in action, there is also a video … Null Pointer Exception in Java Application – Need Fixing 1 Month Ago by YashSmith My Java application crashes with a NullPointerException when trying to access an object property. Here's the problematic code: public class Test { public static void main(String[] args) { String text = null; System.out.println(text.length()); // NullPointerException here }… pointer 20 Years Ago by NIHAR RANJAN …::[/SIZE][/COLOR] [SIZE=2][COLOR=DarkOrange]Pointer is a variable that can hold address value. Pointer to integer is not type of… integer A questain may arises to your mind that why Pointer variable is not declare like… Re: pointer 16 Years Ago by siddhant3s … of p[i] is obviously a pointer-to-int. While the type of p is pointer-to-pointer-to-int. The type of… array of int. Actually, because of the infamous analogy of pointer and arrays, few often ignore that they are actually not…. But strictly speaking, the OP explicitly declared p as pointer-to-pointer-to-int hence p[i] is not an array but… Re: pointer 12 Years Ago by rishif2 …of other variable (i.e Pointer variable's value is address of another variable) Pointer variable has power to access… that referenced variable we can create a variable as pointer type by simply adding the sign `*` for ex:-… int i; int *j; //pointer type variable j=&i; //assigning address to the… Re: Pointer 10 Years Ago by Learner010 … value of a vairable or only takes adress of vairable ?? pointer variable takes address of another variable which must be same…=10; float y; ptr=&y; //Incorrect . Because ptr is pointer to int and it can't be used to point… same.the statement will assign the address of x to pointer ptr print *ptr //*ptr is de referencing(i.e. … Re: Pointer 10 Years Ago by David W … any kind of 'object' ... including the address of an other pointer variable ... and in that case, you then have a… 'pointer to a pointer'. One very common use of pointers is when you allocate… dynamic memory ... The pointer then holds the address to the first byte in that… Re: pointer 16 Years Ago by Bhoot >>now whatever I change in the pointer of a, also gets changed in b. So they both … have understood, i would like to say the following : A pointer actually stores an address of the variable it points to… variable (a character variable in your case) from the pointer value. Say the pointer is char* ptr. Then ptr gives the address… Re: pointer 12 Years Ago by deceptikon … it? A variable holds a value. A pointer's value is an address. How is that…To be strictly correct you'd say a pointer just stores an address. Or if you …especially pedantic, the C standard says that a pointer is an object whose value provides a reference…= malloc(N); The only variable involved is the pointer, so how can you say that it points to… Re: pointer 16 Years Ago by e_agam You can compare the pointer with the location in the memory of the structures (using &) if pointer == &struct ==> the pointer points to that struct. Pointer Help 16 Years Ago by flipjoebanana Hello, I am trying to figure out why pointer address is not preserved over a function call and how …;,argv[0]); return 0; } void test_function(char **argv,char *line) { /* pointer value not kept with this why? */ *argv = line; /* I know… pointer 16 Years Ago by MicrosoftMahmou … you bear with me and help me. in pointer: if i definition a pointer as integer ********************************** int **p = new int*[M]; for… pointer help ~ 14 Years Ago by wildplace im trying to learn pointer n the &(no idea the specific name for it); … of k? can anyone refer sum good tutorial for learing pointer and memoery location stuffs.... they are so confusing >.<… Re: pointer help ~ 14 Years Ago by Fbody …, which you should not do. When you do this, the pointer points at a variable that gets destroyed when the function…) of the variable immediately following it for storage in a pointer. Pointer help 11 Years Ago by chubbyy.putto … so forth. The function should return a pointer to the new array Use ONLY pointer parameters instead of arrays in both functions… Re: Pointer help 11 Years Ago by Banfa …, that means that at line 34 you return an invalid pointer which in main you then try an dereference. This function…** deleted it. The calling function, main, should store the returned pointer and then when it has finished with the new array… Re: pointer 16 Years Ago by manzoor … have a struct, it contains two data members and a pointer to char. I created two objects of the struct and… first like b = a; now whatever I change in the pointer of a, also gets changed in b. So they both… Re: pointer 16 Years Ago by kux of course the pointers in the structs point to the same thing. That is because you do a shallow copy. If you want the two char pointers inside the structs point to diffrent strings you need to do a deep copy ( copy the content pointed by the pointer in a and make the pointer in b point to the new content ). Re: pointer 16 Years Ago by Narue … framework. But my question to you is, what if the pointer isn't pointing to the address of a variable? For… of to what they are pointing ? The value of a pointer is the address that it points to. Re: pointer 15 Years Ago by Ancient Dragon [QUOTE=xfreebornx;1001522]Hello please how can i get a pointer value that is in for loop???[/QUOTE] The star dereferences a pointer [icode]int x = *poionter; [/icode] Re: pointer 15 Years Ago by arshad115 can you explain your question a bit? you can get the value of a pointer by "*". if [code=c++] int x=6; int *y=&x; cout << *y << endl; //get the value of pointer [/code] hope that helps. Re: pointer help ~ 14 Years Ago by Narue … add a level of indirection and make p itself a pointer in main. The same issue exists because pointers are passed… Re: pointer help ~ 14 Years Ago by wildplace @Narue u saved my life... they(pointer n &) still confuse me.., just wonder if u have …