In C++, a map
is an associative container that stores key-value pairs. In this article, we will learn how to find the minimum key in a map in C++.
Example:
Input:
myMap= {{10,"apple"},{5,"banana"},{20,"cherry"}};
Output:
Minimum key: 5
Find the Smallest Key in a Map in C++
There is no direct method available in C++ to find the minimum key in a map. We have to iterate the map elements one by one and find the minimum key by comparing them.
C++ Program to Find the Minimum Key in a Map
The below example demonstrates how we can find the smallest key in a given map in C++ STL.
C++
// C++ program to illustrate how to find the minimum key in // a map #include <iostream> #include <map> using namespace std;
int main()
{ // creating map
map< int , string> myMap;
// inserting key-value pairs in a map
myMap[10] = "apple" ;
myMap[5] = "banana" ;
myMap[20] = "cherry" ;
// Finding the minimum key
auto minKeyIterator = myMap.begin();
// handle the case when map is empty
if (minKeyIterator != myMap.end()) {
// print the minimum key
cout << "Minimum key: " << minKeyIterator->first
<< endl;
}
else {
cout << "Map is empty!" << endl;
}
return 0;
} |
Output
Minimum key: 5
Time Complexity: O(N), where N is the number of elements in the map.
Auxilliary Space: O(1)