How to Iterate Over a Set of Pairs in C++?
In C++, a set is a container that stores unique values in some specified order while pairs are data structures that store key-value pairs. In this article, we will look at how we can iterate through a set of pairs in C++.
For Example,
Input: mySet = { {100: "Geek"}, {200:" for"}, {300:" Beginner"} } Output: Set Elements: Key: 100, Value: Geek Key: 200, Value: for Key: 300, Value: Beginner
Iterate Over a Set of Pairs in C++
In C++, we can simply iterate through the set of pairs using a range-based for loop. After that, we can access the first and second members of the pairs using the dot (.) operator.
C++ Program to Iterator Over a Set of Pairs
C++
// C++ Program to Declare, Insert, and Iterate through a Set // of Pairs #include <iostream> #include <set> #include <utility> using namespace std; int main() { // Declare a set of pairs set<pair< int , string> > s; // Insert the pairs into the set s.insert({ 100, "Geek" }); s.insert({ 200, "for" }); s.insert({ 300, "Beginner" }); // Iterate over the set of pairs through a range-based // for loop cout << "Set Elements:" << endl; for ( auto pair : s) { cout << "Key: " << pair.first << ", Value: " << pair.second << endl; } return 0; } |
Output
Set Elements: Key: 100, Value: Geek Key: 200, Value: for Key: 300, Value: Beginner
Time Complexity: O(N) where N is the number of elements present in the set.
Auxilary Space : O(1)
We can also use iterators and reverse_iterators for forward and reverse iteration of the set of pairs respectively.