lower_bound in map c++
// C++ function for illustration
// map::lower_bound() function
#include <bits/stdc++.h>
using namespace std;
int main()
{
// initialize container
map<int, int> mp;
// insert elements in random order
mp.insert({ 2, 30 });
mp.insert({ 1, 10 });
mp.insert({ 5, 50 });
mp.insert({ 4, 40 });
for (auto it = mp.begin(); it != mp.end(); it++) {
cout << (*it).first << " " << (*it).second << endl;
}
// when 2 is present
auto it = mp.lower_bound(2);
cout << "The lower bound of key 2 is ";
cout << (*it).first << " " << (*it).second << endl;
// when 3 is not present
// points to next greater after 3
it = mp.lower_bound(3);
cout << "The lower bound of key 3 is ";
cout << (*it).first << " " << (*it).second;
// when 6 exceeds
it = mp.lower_bound(6);
cout << "\nThe lower bound of key 6 is ";
cout << (*it).first << " " << (*it).second;
return 0;
}
