map equal_range() in C++ STL

In this tutorial, we will be discussing a program to understand map equal_range in C++ STL.

This function returns a pair of iterators that bounds the range of the container in which the key equivalent to the given parameter resides.

Example

#include <bits/stdc++.h>
using namespace std;
int main() {
   //initializing container
   map<int, int> mp;
   mp.insert({ 4, 30 });
   mp.insert({ 1, 40 });
   mp.insert({ 6, 60 });
   pair<map<int, int>::iterator,
      map<int, int>::iterator>
      it;
   it = mp.equal_range(1);
   cout << "The lower bound is " << it.first->first<< ":" << it.first->second;
   cout << "\nThe upper bound is "<< it.second->first<< ":" << it.second->second;
   return 0;
}

Output

The lower bound is 1:40
The upper bound is 4:30