In C++, a map is a container that stores elements in key-value pairs, where each key is unique and associated with a value. In this article, we will learn how to add multiple key-value pairs to a map in C++.
Example:
Input: myMap = {{1, "one"}
}; Elements to be insert = {{2, "two"}, {3, "three"}}
Output: myMap = {{1, "one"}, {2, "two"}, {3, "three"}}
Map Multiple Key-Value Pairs in C++
To map multiple key-value pairs to a std::map in C++, we can use the std::map::insert function that inserts key-value pairs into the map. The insert function can take a pair, a range of pairs, or an initializer list of pairs. Here, we will insert the range of pairs defined in the initializer list.
C++ Program to Map Multiple Key-Value Pairs
// C++ Program to illustrate how to insert multiple key // value pairs in a map #include <iostream> #include <map> using namespace std;
int main()
{ // Creating a map
map< int , string> myMap = { { 1, "one" } };
// Adding multiple key-value pairs to the map
myMap.insert({ { 2, "two" }, { 3, "three" } });
// Printing the map after adding the key-value pairs
cout << "Map after adding multiple key-value pairs:"
<< endl;
for ( const auto & pair : myMap) {
cout << pair.first << " => " << pair.second << endl;
}
return 0;
} |
Map after adding multiple key-value pairs: 1 => one 2 => two 3 => three
Time Complexity: O(M logN), where M is the number of new pairs and N is the size of the map.
Auxiliary Space: O(M)