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
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Memory taken by a vector of vectors
What is the expected difference (if any) in memory taken by vvint1 and vvint2?
Is vitest1 copied into a new memory position each time a push_back takes place?
Is vitest2 copied into a new memory position each time a push_back takes place?
typedef…
sancho.s ReinstateMonicaCellio
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When it comes to a sequence, is "vector[n].push_back()" is always O(1)?
I've used vector v[N] a lot.
It's a very powerful tool for me.
I wonder v[n].push_back() costs O(1) on average.
I know when the vector is full, it needs to expand into double.
But isn't the sequence of vectors attached to each other?
If so, I…
marks jun
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How to display all elements in vector
When I try to display all elements in the vector, it only display name of dealer, and number of dealer, but number of cars is MISSING! So how do I display the whole vector completely?
I declare a vector in Main and pass it to the readIn and display…
Lin
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1 answer
Execution is halting at push_back
The following for loop halts execution at the first cycle, and I have no clue why. I have figured out by placing couts in it that it stops at the push_back. It was working before, then I tried modifying it, then I did Ctrl-z to get it back to this…
sqrtoiler
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Can anyone explain why push_back() causes a SEGFAULT here?
I've been getting a segfault and I narrowed down where the issue comes up by simplifying my main() function and using valgrind.
main.cpp
int main() {
unique_ptr g1 = make_unique();
unique_ptr g2 = make_unique();
…
Nick Nagy
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1 answer
Copy constructor get called more than one time
Below code outputs:
Default ctor is called
Copy ctor is called
Default ctor is called
Copy ctor is called
Copy ctor is called
Why for each push_back() the calling of copy constructor incremented by 1?
I think it should only be called one time.
Is…
Islam Abdeen
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Implement a class want to simulate std::string but get stuck when push_back it into a vector
I have implemented a class String. When I push_back a String object to a Vector, the program gets stuck. Please help me review it if you're interested.
String.h
#pragma once
#include
#include
#include
class String…
Zhen Yang
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C++: push_back() function doesn't append double values: segmentation core dumped
I am having trouble with the push_back() function in C++. For a reason which I don't understand, the push_back function will "not accept" the value I am telling it to append, but the code works perfectly until I try to display the values I want (end…
Joachim
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free(): invalid next size (fast) for resizable vector
I'm trying to implement a resizable vector in C without using the realloc and calloc functions. However, when I try to push a lot of values to the back of the array, I get a free(): invalid next size error. How can I remedy this?
I tried freeing the…
bamfot13
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I'm having difficulties splitting a string into a vector
I'm trying to write code that initializes a string into a vector by splitting it at every space character. Somehow the temporary vector won't take the positions and it doesn't split the string right.
#include
#include
#include…
Demonic-Coder
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List items and iterators: do either push back or iterators create copies of original data?
Though I've a lot of experience as C Embedded Programmer, I'm actually not so skilled in C++. I'm implementing a parser in which ItemsToBeFound are pushed within a list.
It happens that some of these items (let's say master items) carry more…
Roberto Caboni
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2 answers
Why does push_back into vector> causing seg fault?
Want to construct a Graph with adjacency list, but getting seg-fault when I add elements to vector>. adj.size() prints 5 which tells it has allocated memory, why the seg-fault in addEdge() method?
#define V 5
struct Edge {
…
a k
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2 answers
Issues related to user input array elements in one line in c++
I am coding a very basic problem but I am stuck in reading input of an array in one row. I have used the technique used mentioned in How to user input the array elements in c++ in one line but I see that it doesn't work and it gives 'segmentation…
Hamsa
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How can I add row or col in the left of the matrix?
I know how to add row or col in the right of the matrix:
cv::Mat row = cv::Mat::ones(1, 3, CV_64F); // 3 cols, 1 row
m.push_back(row); // 3 cols, 5 rows
But I don't know how to add row or col in the left of the…
user11690510
0
votes
2 answers
Push_front and push_back methods for linked list seems to remove a node
I'm writing a class called Playlist which performs different operations on PlaylistNodes. I looked online and tried to implement push_back and push_frontmethods, but I was unsuccessful.
PlaylistNode *PlaylistNode::insert_next(PlaylistNode *p) {
…
MZP
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