is the action of adding an element at the end of a container.
push-back is the action of adding an element at the end of a container.
Questions tagged [push-back]
420 questions
-1
votes
1 answer
Error regarding Copy constructor and pushback method of vector
using namespace std;
class test {
public:
int p;
test() {
cout << "base" << endl;
}
test(int x) {
p = new int;* p = x;
cout<<"args" << endl;
}
test(test & args) {
p = new int;
…
gabbar
- 49
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-1
votes
3 answers
Is there a more efficient way for storing vector> ? C++
The real file I read is about 15.000 kBs. Thus I am not sure whether this is the best way of storing such a data structure.
Here is the code.
string line;
ifstream File;
vector> v;
string filename =…
Emin Baybars Timur
- 87
- 1
- 5
-1
votes
1 answer
error: no matching member function for call to 'push_back'/ String vectors
The problem is like this: Given two arrays of strings a1 and a2 return a sorted array r in lexicographical order of the strings of a1 which are substrings of strings of a2.
EX:
Input: a1= arp, live, strong.
a2 = lively, alive, harp, sharp,…
Maria
- 71
- 10
-1
votes
4 answers
How to push_back() C array into std::vector
This doesn't compile:
vector v;
int p[2] = {1, 2};
v.push_back(p); //< compile error here
https://godbolt.org/z/Kabq8Y
What's the alternative? I don't want to use std::array.
The std::vector declaration on itself compiles. It's the…
tuket
- 3,232
- 1
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- 41
-1
votes
2 answers
C++ push_back many 1D vectors in a 2D vector
Let's say i have a lot of vectors :
vector v1 = ...
vector v2 = ...
...
vector v1000 = ...
Is there a quicker way to populate a 2D vector with those 1D vectors than this :
vector> vGlobal…
Viroun
- 1
-1
votes
1 answer
Why vector.push_back(s) does not work here but vector[i]=s works(mentioned as comment)?
Why vector.push_back(s) does not work here but vector[i]=s works (mentioned as comment)? If I use the push_back function, nothing gets printed. vec[i]=s works perfectly fine, but why is the push_back not working? I expect both the alternatives to…
AMIT PRASAD
- 1
- 2
-1
votes
1 answer
Does push_back change the structure of type stored in its vector?
I have following 2 classes:
class Core
{
public:
Core() : mid(0), fin(0) {}
Core(std::istream &in)
{
read(in);
}
virtual ~Core() {}
Str name() const
{
return n;
}
virtual double grade() const
…
milanHrabos
- 2,010
- 3
- 11
- 45
-1
votes
3 answers
insert string into vector character by character
I'm trying to insert the characters of the string into a char vector but place the letters in reverse order . can anyone tell me why this doesn't work
int main()
{
string a = "Hello";
vector arr(5);
for(int i = 4 ; i == 0 ;…
jeffrey pernia
- 33
- 1
- 7
-1
votes
1 answer
Are these variants of std::vector::push_back constant or linear?
We all know that std::vector::push_back has constant (amortized) complexity.
It is constant because we say that the amortization cost is negligible, doubling every time. With reallocation being linear complexity.
Let's change our std::vector…
dau_sama
- 4,247
- 2
- 23
- 30
-1
votes
1 answer
c++ - runtime error: vector push_back()
Please tell me reason why this code have runtime error.
I think that addEmployee() function is problem.
#include
#include
#include
using namespace std;
enum EmployeeLevel {fresh, sophomore, junior, senior};
class…
doubleU
- 13
- 2
-1
votes
1 answer
How can I avoid extra copying when constructing a vector to be returned?
C++ newbie here! I wrote a code who is considering a WORLD which made of a vector of CITIES. This world gets updated nbTimeStep times. Here is a rough summary of what my code looks like. For ease of reading, all class names are in all caps.
//…
Remi.b
- 17,389
- 28
- 87
- 168
-1
votes
1 answer
Push_back is replacing current point instead of adding a new one to the vector
I am having trouble appending new points onto the end of my current Vector of points. What it is currently doing is overwriting the existing vector with the new point I am trying to add, leaving the vector with only 1 element.
This is the class…
James Mallett
- 827
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- 27
-1
votes
1 answer
Inserting in a list changes values c++
I want to create multiple "voxel"-objects and put them in a list. But if I do so two of the values, that are stored by voxel, change.
Here is the class definition:
class Voxelization{
private:
int sf_counter;
bool subdiv;
int seg_fac;
int*…
Sven
- 81
- 1
- 13
-1
votes
1 answer
c++ adding objects to vector destroys earlier objects
I need to add objects of the same class to a vector:
#include
#include
class A {
int *array;
int size;
public:
A(int s) {
array = new int[size = s];
fprintf(stderr, "Allocated %p\n", (void*)array);
…
pVinken
- 23
- 4
-1
votes
3 answers
What exactly happens when I do buffer1.push_back(buffer2.front()) in C++?
Help me understand this.
Here is the context.
I am writing a program in C++.
I have 2 buffers (deque). Let's call them buffer1 and buffer2;
I have 2 threads: one thread is filling buffer1 with random values. The other one is copying the oldest…
Filipe Santos
- 61
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