In C++, `std::set`s are a kind of associative container that stores unique elements, and in which the elements themselves are the keys.
Questions tagged [stdset]
294 questions
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0 answers
std::set using class pointers. How to control insert
I have been google all over the place and am unable to find a working example for how to use std::set and control the insert order. I found comments for my type of structure but I get a compile error.
I am trying to sort on myMaskName so I get
…
user3416126
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Is it somehow possible to pass a set constructor a lambda function with a non-empty capture list as the set's compare function?
I have a struct:
struct some_struct {
int i;
char c;
};
Now I want to put it in a std::set using a custom compare function:
set s_s(
[](some_struct* s1, some_struct* s2)->bool…
user4385532
0
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2 answers
required from 'std::pair, bool> std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_M_insert_unique
I'm getting a compilation error,
required from 'std::pair, bool> std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_M_insert_unique(_Arg&&) [with _Arg = Solution::EnhancedNode* const&; _Key =…
Andrew Cheong
- 29,362
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2 answers
std::set doesn't detect duplicate custom objects
I have a map for keeping the team name and players of the team std:pair > and a set of pointers to players to keep the players sorted in descending order by wins. And there's the catch - one player can…
Стоил Янков
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Can't insert elements in a set of sets
I have a structure with some properties and a set. I have multiple instances of those structs inside another set. When I try to add something to the set inside the struct:
test2.cpp: In function ‘int main()’:
test2.cpp:42:22: error: no matching…
Joaquim Ferrer
- 603
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2 answers
std::set
I've tried to use set to keep some configurations in a trie lately.
I've found a doubt on the comparator, for instance :
#include
#include
using namespace std;
struct Node{
int position;
int…
Ruan Kotovich
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3 answers
How to remove items from position i in std::set?
std::set tmp_{30, 40};
int i=0;
while(tmp_[i]==40)
{
i++;
}
tmp_erase(i);
How do I remove an element at position i?I cannot use erase because i is not std::set::iteretor
M.Devan
- 169
- 2
- 13
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2 answers
C++ std::set with a custom lower_bound
How would I perform a find() or lower_bound() function on a std::set using a comparator function that is independent of its key such that it still runs in O(log N) time?
Suppose I define a data type foo with two variables x and y and have a…
Muhammad Irham Rasyidi
- 73
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4 answers
Bug in C++ Set?
When I tried this part of the code:
int x=*(s.rbegin());
while(!s.empty()&&0
Stan Zhang
- 21
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1 answer
Return an iterator to boost multiintex container as a std::set<>::iterator
The documentation for Boost multiindex containers seem to indicate that I can use it as a set after declaring an index to iterate over. So I was wondering if it is possible to hide the boost implementation and return an iterator masqueraded as an…
xcorat
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0
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2 answers
Base class of sorted containers in C++
Does C++ have a common base class for sorted containers like std::set or std:map?
Background: I want to implement a generic function which deletes all elements in a container which are not found in another container. As a precondition I want to…
user1056903
- 921
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0
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0 answers
Remove a shared_ptr from std::set without using boost library in order to delete an edge from a graph's edges_
I have a std::set declared as the following:
std::set> edges_;
I want to remove a shared_ptr, effectively one of the edges stored in edges_, from the set. It does go into the if loop where it prints that it has found the edge,…
iteong
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Implement a custom compare class for std::set (using std::shared_ptrs) that compares edge objects of a directed weighted graph
I'm trying to delete an edge from edges_, which is stored in a Graph class Node struct as a std::set using std::shared_ptr:
template class Graph {
private:
struct Node;
struct Edge;
struct…
iteong
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1 answer
Deleting an edge from edges_ that is declared as std::set> edges_;
I'm new to std::shared_ptr and std::set. For the following code, I want to know how I can delete the edge from edges_.
edges_ is declared as std::set> edges_; and I want to delete the edge referenced by the shared pointer…
iteong
- 715
- 3
- 10
- 26
0
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1 answer
Deleting edges for a node in a directed weighted graph that uses smart pointers
I'm pretty new to shared pointers and am trying to delete a node from the graph. When I delete a node, the incoming and outgoing edges stored in that node will be deleted. However, I also need to delete the outgoing and incoming edges (which is the…
iteong
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