In C++, a stack is a container adapter that provides a Last-In-First-Out (LIFO) type of data structure, and an unordered set is a container that stores unique elements in no particular order. In this article, we will learn how to create a stack of unordered sets in C++.
Creating a Stack of Unordered Sets in C++
To create a std::stack of std::unordered_set, we can use the std::stack template class that takes the type of the elements as a template parameter. We can define this type as of unordered_set of a given type.
Syntax to Declare Stack of Unordered Set
stack<unordered_set<Type>> myStack
C++ Program to Create Stack of Unordered Set
C++
// C++ program to illustrate how to create a stack of // unordered sets in C++ #include <iostream> #include <stack> #include <unordered_set> using namespace std;
int main()
{ // Declaring a stack of unordered sets
stack<unordered_set< int > > myStack;
// Creating some unordered sets
unordered_set< int > set1 = { 1, 2, 3 };
unordered_set< int > set2 = { 4, 5, 6 };
unordered_set< int > set3 = { 7, 8, 9 };
// Pushing unordered sets into the stack
myStack.push(set1);
myStack.push(set2);
myStack.push(set3);
// Checking if the stack is empty
cout << "Stack Elements: " << endl;
while (!myStack.empty()) {
auto ele = myStack.top();
int count = 1;
cout << "uSet" << count << ": " ;
for ( auto i : ele) {
cout << i << " " ;
}
count++;
cout << endl;
myStack.pop();
}
return 0;
} |
Output
Stack Elements: uSet1: 9 7 8 uSet1: 6 4 5 uSet1: 3 1 2
Time Complexity: O(N) where, N is the number of unordered sets.
Auxiliary Space: O(N)