Find Last Key in a std::map in C++
To find the last key-value pair in a std::map, we can use the std::map::end() function which returns an iterator pointing to the imaginary element after the last element of the map container with a combination of std::prev() to get access to the last key-value pair in the map.
C++ Program to Find the Last Key-Value Pair in a Map
The below example demonstrates how we can find the last key-value pair in a map in C++ STL.
C++
// C++ Program to illustrate how to find the last element in // a map #include <iostream> #include <map> using namespace std; int main() { // Initialize a map with some entries map< int , string> myMap = { { 1, "C++" }, { 2, "Java" }, { 3, "Python" }, { 4, "JavaScript" } }; // Find the last key-value pair of the map auto lastPair = prev(myMap.end()); // Print the last key-value pair of the map cout << "Last Key-Value pair in the Map is : {" << lastPair->first << ", " << lastPair->second << '}' << endl; return 0; } |
Last Key-Value pair in the Map is : {4, JavaScript}
Time Complexity: O(1)
Auxiliary Space: O(1)
How to Find the Last Element in a Map in C++?
In C++, a map is a container provided by the STL library that stores data in key-value pairs in an ordered or sorted manner. In this article, we will learn how to find the last key-value pair in a Map in C++.
Example:
Input:
Map: {{1, "C++"}, {2, "Java"}, {3, "Python"}, {4, "JavaScript"}};
Output:
Last Key-Value pair in the Map is : {4, JavaScript}