C++ :: How To Remove Element Of A Vector And Returning It
Sep 22, 2014pop_back just returns void, so I just can't use that?
erase is okay but it doesn't return anything....
Do I use a combination of both?
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C++ :: Sequentially Remove One Element From Vector At A Time With Replacement?
Dec 8, 2014I have a vector of int,
Code:
vector<int> row_numbers{1,2,3,4,5,6,7,8,9};
I want to sequentially remove one element at a time starting with the first. When the second element is removed, the first element needs to go back in. The sequence would look like
Code:
// original vector, row_numbers.size()=9
row_numbers{1,2,3,4,5,6,7,8,9};
// trimmed vector, row_numbers_trim.size()=8
[Code] .......
I have been working under the assumption that the best method would be to have row_numbers remain untouched and work on a copy. For each step in the sequence, you would create row_numbers_trim as a copy of row_numbers, and then remove an element from row_numbers_trim.
Code:
// position being removed
int counter = 0;
// copy original vector
row_numbers_trim = row_numbers;
// remove the first element from the copy
row_numbers_trim(row_numbers_trim.begin()+counter);
All you would have to do here is to increment counter in a loop. is there a better way?
C :: Remove Array Element?
Jan 27, 2013I want to a C program to delete an element from an array which can use both index method & character method
For example
input : "1 222 333 4444"
output:"1 22 333 4444"
if either index = "4" or character ="2" is entered
It should able to read in/accept any input array of varying length, and the position/index or element in array to be deleted...
C++ :: How To Remove Element In A List
Mar 27, 2013How can I remove an element in a list when I have only an iterator that points to the object I want to remove. Is there a build in command? remove() takes an object reference as its argument. Is it possible to convert the iterator into a pointer type so it can be deferenced and passed to remove?
This is the code I am working on:
//player.cpp
void Player::CheckCollectableCollisions(std::list<Collectable>& c) {
std::list<Collectable>::iterator i = c.begin();
while(i != c.end()) {
if (Collider::CheckCollision(pNodes_.front().getLocation(), i->getLocation()))
[Code] .....
C++ :: Remove Element From Linked List?
Jun 6, 2013This code is from a example in Jumping Into C++ and I understand the example. But it is a practice problem that is to write a program to remove an element from a linked list; the remove function should take just the element to be removed.
Code: #include <iostream>
using namespace std;
struct EnemySpaceShip {
int x_coordinate;
int y_coordinate;
[Code]...
If I got this right I will create a pointer that points to the first SHIP (getNewEnemy) and the other one will not be printed out.
C++ :: Remove Element In Linked List
Oct 17, 2014This is my current code. The code is to remove the element in the list "head" that is "e". The code works if there is only one element in the list but if there are more than 1 element in the list, it doesn't work. The function should return true if there is an element that equals "e" and then it removes it and false if no element equals "e".
bool StringLinkedList::remove(const std::string& e){
StringNode* current = head;
int i = 0;
if (current == NULL)
return false;
[Code] ....
C++ :: Remove Element From Array By Using Function?
Jun 2, 2013how i can remove element from array by using function?
View 3 Replies View RelatedC Sharp :: How To Remove First Element From Int Array
Nov 14, 2012I'm currently trying to remove the first element in an int array using objects in C#. I have just coded how to add an element to that start of the array and though it was just a case of changing a few things.
Here's the code for the addFirst() but i can't for the life of me figure out removeFirst()
public void addFirst(int value) {
if (isFull()) {
throw new Exception("List full");
[Code] ....
C/C++ :: Remove All Instances Of Element Within List - While Loop Error
Jun 23, 2014I am getting an error with my while loop(feels dumb) when running this code that I am allowed to modify. It is to remove all instances of an element within the list.
The loop is whithin this function:
void arrayListType<elemType>::removeAll(int location)
I have attached both the header file and main function file in .txt format.
void arrayListType<elemType>::removeAll(int location)*
Attached File(s) :
header.txt (12.23K)
main function.txt (2.95K)
C++ :: Remove Duplicated From Sorted Vector
Dec 1, 2014I have vector pair like below, it is sorted but I want to remove duplicate values: The vector is like below:
std::vector<std:air<std::string,double>> fileWeight;
Here is what in vector:
scene1.jpg 0.4
scene2.png 0.4
scene3.jpg 2.3
scene4.jpg 4.1
The highlighted top 2 are duplciated. How can I remove duplciated like this where I have to check whole pair?
C++ :: Returning Reference Of Vector
Sep 6, 2013Example code:
Code:
#include <iostream>
#include <vector>
using namespace std;
class A{
[Code]....
I read somewhere, that we can imagine the reference as a pointer to the vector. So, my question is:
Let's assume that instance of class A, named a, was created with new. We call a.getV() to foo and then we call the destructor of a. foo is safe? Is the copy constructor of std::vector called?
C/C++ :: Function Isn't Returning A Vector
Nov 11, 2014I am writing a function to take two vectors and put them end to end in a third vector. I'm new to working with vectors, and I cannot figure out why my append function is not returning vector C. I had the function print out vector C within it to make sure the logic in the function wasn't the problem, and it worked perfectly. My code is as follows:
#include <iostream>
#include <vector>
using namespace std;
//append function to put vector b after vector a in vector c
vector <int> append(vector <int> a, vector <int> B)/>/>/> {
vector <int> c;
[code]....
and my output is as follows:
Vector A contains: 10 18 123 172
Vector B contains: 283 117 17
The two vectors back to back are:
Obviously, the third vector is not returning from the function to main properly, but why.
C++ :: Sort / Find Duplicates And Remove From Vector
Nov 18, 2013I'm trying to sort my vector, find duplicate values using unique and erase them. Program can compile successfully but the duplicates are not removed.
output:
x: 3
y: 2
x: 6
y: 4
x: 3
y: 2
vector<Point2D> p2dvector;
void readData()
[Code].....
I also have operator== in my Point2D class which I understand it is required to use unique for vector.
bool operator==(const Point2D& lhs, const Point2D& rhs)
{
return lhs.x == rhs.y;
}
C++ :: Remove Duplicates Vector Of Strings But Keep First Instance - Cannot Use Algorithm
Mar 18, 2014I have a vector of
strings.vector input;
bob
sam
bob
sammom
aardvark
money
aardvark
wanted
I need to remove the duplicates but each part of the vector corresponds to the next location. They are pairs.
ex. bob corresponds to the its definition, which is sam.
I need to keep the first instance, so keep bob and sam, but remove the second instance of bob, so remove bob and sammon. Only the first instance of the pair need to kept.
It doesn't matter if the sam and sammon don't match, all that matters is the first part of the pair.
The vector is already in alphabetical order. I can't use the algorithm library.
C++ :: How To Insert Element Into A Vector At Particular Index
May 3, 2013I am storing info in a vector but I want to store certain info at a particular index. I am new to using vectors and am unsure about have to do this. I am aware of the insert method but am confused on how to use it to store at a particular index.
View 1 Replies View RelatedC++ :: Pop Element On A Vector Off And Return Its Value At Same Time
Sep 6, 2014I am trying to pop the element on a vector off and return its value at the same time
vector.push_back();
Unfortunately that code only removes that element from the vector it does not return it
Is the only way to get the element and destroy it is to do this?
vector.back();
vector.pop_back();
C++ :: How To Access Element Of Point3f Vector
Aug 4, 2013How to access an element of the point3f vector. E.g. :
int main() {
vector<Point3f> a;
a.push_back(Point3f(0,0,0);
a.push_back(Point3f(0,0,1);
//print first x,y,z element
cout<<a[0]<<endl;
[Code] ...
But it doesn't work firstly because it says can't use typename i.e. <float>
C++ :: Search A Vector Element With Multiple Strings?
Nov 22, 2013How could I search a vector element with multiple strings
i.e. vector.at(i) = This is a test
How could I search that to look for the word "test" in that element?
C++ :: Using Istringstream To Read Each Word Of Each Element In Vector
Mar 6, 2014Consider I have a vector of strings and then I use an istringstream to read each word of each element in the vector, why do I nescessarily use an istringstream?
This is the code that does what I just described (I think)..
Code:
for(auto &elem : svec) {
istringstream strm(elem);
while (strm >> word)
//Magic
}
What would be the equivalent of using something else than an istringstream in this scenario and how does the istringstream work?
C++ :: Changing Class Type Of A Vector Element?
Aug 16, 2014I am programming a 2-D platformer video game. The stages are composed of an array (really a vector) of 16x16 px^2 tiles. I have defined a base class "Tile" and several derived classes, e.g., "Ramp", "Door", etc., which have their own attributes. The idea is that upon entering a room, the program will load all of the necessary tile data for that room into a vector. So, I have a vector that looks like: vector <Tile*> room_tiles, and resize it based on the total number of tiles in the room: room_tiles.resize(Tile_Count). I then want to read in certain info from the data file containing all of the tile information for that room. For example, if the data file says Tile 5 should be a ramp, I want to change the 5th element of the room_tiles vector to the derived ramp class. This is really where I'm having trouble. I've worked with vectors of base and derived classes before, but those were always of indeterminate size and I always used something like: (Vector).push_back(new DerivedClass()) to specify the derived class of that element. The problem is that that method only seems to work if you are appending elements to the end of a vector.
how I can do this?
C++ :: Filling Vector From A File - Adding Empty Element At The End
Apr 20, 2014I'm having a problem filling a vector from a file. Basically, it is adding an empty element at the end. I'm new to Qt and haven't worked with file streams much so how to stop the stream before it adds the extra element.
void gui::get_data() {
mileage.clear();
QFile file(file_label->text() + ".txt");
QTextStream in(& file);
float m;
float g;
QString d;
[Code] ....
But, if I add another element to the vector and write that the file look like this.
//file after adding element
132654 0 02132014
132654 0 02132014
0 0
132998 22 02202014
I have it set to append at the moment so that is why the first line is repeated. I figure the problem is with if(in.atEnd()). I could fix it by deleting the last element right after adding it, but that seems like more of a hack than anything else.
Visual C++ :: Selecting 1 Element From Each Vector Without Duplication Of Any Combination
Jul 15, 2013I have N vectors which look like this:
[1→m] [m+1→2m] [2m+1→3m] [3m+1→4m] [4m+1→5m]..... [{(N-1)m}+1→Nm]
I want to select 1 element from each vector without duplication of any combinations. Essentially only when all combinations are done with 1st element in first vector ,only then it should move to next element in first vector.
Say i have elements :[123] [456] [789]
my combinations should be like
147
148
149
157
158
159
167
168
169
247....
Also, I cant have any repetitions and only after all combinations of 1 are done only then the loop has to move to next combination ie 247 combination and so on.
I tried NCK (n choose k) command but it gave me random combinations. How should i go about it with using minimal for loops?
C++ :: Linked List - Function Which Deletes Element If Next Element Is Bigger
Mar 10, 2014So I have linked list and function which deletes element if next element is bigger, so my code is working but its not working with first element, in the comment I have wrote code which I would code for checking that first element, but when ever I check it is blowing up all program.
#include <iostream>
using namespace std;
struct llist {
int x;
llist *next;
[Code] .....
C :: Last Element Of List Overwritten By First Element Of Another
Feb 23, 2013I have a global list that contains smaller lists of char arrays. I have an issue where when I'm reading back the inner lists the last element of one list seems to point to first element of the next.
So my data looks like the below (values separated by commas with the pairs separated by tabs. The last pair in a line is the same as the first). When I read the first list back instead of seeing "456.678,678.98" as the last element in the list. I see "435.67,234.98" twice: at the end of the first list and start of the other. I have debugged when the list is populated and can see the correct values going in so I can't figure what's happening.
456.678,678.98 123.45,345.56 256.67,789.98 456.678,678.98
435.67,234.98 123.65,342.56 987.78,678.34 435.67,234.98
Code to fill the list:
obstacle_list = op_prg_list_create();
while (fgets(line, sizeof(line), obstaclePositions_traj_file) ) {
token = strtok(line, "
"); //Pull the string apart into tokens using the
input = op_prg_list_create();
[Code] ....
C++ :: Std List - How To Get Value Of Element 2 Minus Element 1
Aug 23, 2012I have an std list of type double.. and the list is always guaranteed to have just 2 elements. I need to get the value of element 2 minus element 1. What is the least amount of code to accomplish that?
I tried this:
Code:
list<double> dList;
dList.push_back(1.0);
dList.push_back(2.0);
list<double>::iterator iter = dList.begin();
list<double>::iterator iter2 = dList.end();
double result = *iter2 - *iter;
But this code does not work. Why not?
C++ :: Using Vector Push Back Function To Output Contents Of Vector (similar To Array)
Feb 9, 2015How to output vector contents using the push_back function. My program reads in values just fine, but it does not output anything and I've been stuck on why.
here is my code:
#include <iostream>
#include <array>
#include <vector>
using namespace std;
int duplicate( vector < int > &vector1, const int value, const int counter)
[Code].....