swap

I have an array of objects a=[ {v:0}, {v:1}, {v:2}, {v:3} ] ; I do not have the index into the array, but I do have references to the 2 values I want to swap s1=a[2] ; s2 = a[3] ; How do I use these references to swap the elements of the actual array? [s1,s2] = [s2,s1] ; // only swaps s1 and s2, NOT elements of the array // a is unchanged Mosè Raguzzini If you have the reference you can safely retrieve the index by Array.indexOf() : a.indexOf(myReference) // returns the index of the reference or -1 Then, with retrieved index, you can proceed as usual. Like this: let a = [{ v: 0 }, { v: 1 }, {

I am trying to swap two nodes in a doubly linked list. Below is the part of program having swap function. int swap (int x, int y) { struct node *temp = NULL ; struct node *ptr1, *ptr2; temp = (struct node *)malloc(sizeof(struct node)); if (head == NULL ) { printf("Null Nodes"); } else { ptr1 = ptr2 = head; int count = 1; while (count != x) { ptr1 = ptr1->next; count++; } int count2 = 1; while (count2 != y) { ptr2 = ptr2->next; count2++; } ptr1->next->prev = ptr2; ptr1->prev->next = ptr2; ptr2->next->prev = ptr1; ptr2->prev->next = ptr1; temp->prev = ptr1->prev; ptr1->prev = ptr2->prev; ptr2-

Hi I'm trying to do a simple swap of two objects.My code is void Main() { object First = 5; object Second = 10; Swap(First, Second); //If I display results it displays as //Value of First as 5 and Second as 10 } private static void Swap(object First, object Second) { object temp = First; First = Second; Second = temp; } Since objects are reference type, its reference should be passed to method and it should swap. why is it not happening? There's various different things here: the objects live off in the heap. Forget about them for now the references to the objects are what get stored in First

Thanks Doug. Here's the fix: void swap(int& a, int& b) { if (&a == &b) // added this check to ensure the same address is not passed in return; a ^= b; b ^= a; a ^= b; } I am implementing quicksort for fun in C++, and I am using integers for dummy data. I had been using the XOR swapping algorithm to swap two values in place, but I noticed my sort was screwing up. I changed my swapping algorithm and it worked. I added some debugging statements, and found that the XOR swap was doing something weird. I printed the data before and after I swapped it, and this is what it printed: ... swapping -5, -3

I have read several sources that discuss how to swap two numbers without using a third variable. These are a few of the most relevant: How do you swap two integer variables without using any if conditions, casting, or additional variables? Potential Problem in "Swapping values of two variables without using a third variable" Swap two integers without using a third variable http://www.geeksforgeeks.org/swap-two-numbers-without-using-temporary-variable/ I understand why it doesn't make sense to use the described methods in most cases: the code becomes cluttered and difficult to read and will

How can I go about swapping numbers in a given list? For example: list = [5,6,7,10,11,12] I would like to swap 12 with 5 . Is there an built-in Python function that can allow me to do that? >>> lis = [5,6,7,10,11,12] >>> lis[0], lis[-1] = lis[-1], lis[0] >>> lis [12, 6, 7, 10, 11, 5] Order of evaluation of the above expression: expr3, expr4 = expr1, expr2 First items on RHS are collected in a tuple, and then that tuple is unpacked and assigned to the items on the LHS. >>> lis = [5,6,7,10,11,12] >>> tup = lis[-1], lis[0] >>> tup (12, 5) >>> lis[0], lis[-1] = tup >>> lis [12, 6, 7, 10, 11, 5]