How can I create custom algorithms using C++ STL?

How can I create custom algorithms using C++ STL?

You can create custom algorithms in C++ STL by defining your own functions and using them with STL algorithms like std::sort or std::transform. Would you like an example?

Yes, please provide an example of a custom sorting algorithm.

Sure! Here's a simple example of a custom comparator for sorting a vector of pairs based on the second element:

#include <vector>
#include <algorithm>
#include <iostream>

bool customComparator(const std::pair<int, int>& a, const std::pair<int, int>& b) {
    return a.second < b.second;
}

int main() {
    std::vector<std::pair<int, int>> vec = {{1, 3}, {2, 1}, {3, 2}};
    std::sort(vec.begin(), vec.end(), customComparator);
    // Now vec is sorted based on the second element.
}

That's great! Can I use lambda functions for custom algorithms?

Absolutely! Lambda functions are a great way to define custom algorithms inline. For example, you can replace the customComparator with a lambda like this:

std::sort(vec.begin(), vec.end(), [](const std::pair<int, int>& a, const std::pair<int, int>& b) {
    return a.second < b.second;
});