Lambdas in C++

lambda.cpp

#include <iostream>   // std::cout
#include <string>     // std::string
#include <vector>     // std::vector
#include <algorithm>  // std::count_if, std::adjacent_find, std::sort
#include <numeric>    // std::accumulate
#include <functional> // std::function
#include <array>	  // std::array

void printIt(const std::function<int(const std::string& word)>& fnc, const std::string& word) {
	std::cout << fnc(word) << "\n";
}

int main() {

	printIt([](const std::string& word)-> int { return word.length(); },
	        "Hello Class!!!!");

	std::vector<std::string> words{
		"the", "origin", "of", "consciousness", "in", "the", "breakdown", "of", "the", "bicameral", "mind"
	};

	int longWordLength;

	std::cout << "Define the length of a 'long word': ";
	std::cin >> longWordLength;

	// Count the number of words with a length greater than 8.
	const int longWordCount = std::count_if(words.begin(), words.end(),
	                                        [=](const std::string& word)-> bool {
		                                        return word.length() >= longWordLength;
	                                        });

	std::cout << "There are " << longWordCount << " words greater or equal in length to " << longWordLength <<
		" characters.\n";

	// Find the sum of the lengths of the words.

	const double sumOfLengths = std::accumulate(words.begin(),
	                                            words.end(),
	                                            0,
	                                            [](const double sum, const std::string& word)-> double {
		                                            return sum + word.length();
	                                            });

	std::cout << "The sum of the lengths of the words is: " << sumOfLengths << "\n";

	// Calculate the average length of the words. (sum / # of words)

	std::cout << "The average length of our words is: " << (sumOfLengths / words.size()) << "\n";

	std::array<std::string, 12> months{
		"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November",
		"December"
	};

	// Find the first two consecutive months that start with the same letter.
	const auto sameLetter{
		std::adjacent_find(months.begin(), months.end(),
		                   [](const auto& a, const auto& b) { return a.size() == b.size(); }
		)
	};

	if (sameLetter == months.end()) {
		std::cout << "Sorry, nothing found.";
	} else {
		std::cout << *sameLetter << " and " << *std::next(sameLetter)
			<< " have the same length.\n";
	}


	std::array numbers{
		9, 99, 4, 44, 300, 3, 12, 2, 200,
		3, 23, 1, 2983, 23, 123, 23, 19282, 45
	};

	int numberOfComparisons = 0;

	std::sort(numbers.begin(), numbers.end(),
	          [&](auto a, auto b) {
		          numberOfComparisons++;
		          return a > b;
	          }
	);

	std::cout << "The sort required " << numberOfComparisons << " comparisons.\n";

	for (const auto number : numbers) {
		std::cout << number << " ";
	}
}