#include <iostream>
#include <string>
#include <algorithm>
#include <iomanip>
 
int main() {
	//make lower
	std::string a = "HELLO";
	std::transform(a.begin(), a.end(), a.begin(), ::tolower);
	std::cout << a << std::endl;
 
	//reverse string
	std::string b{a.rbegin(), a.rend()};
	std::cout << b << std::endl;
 
	//contains
	bool c = (b.find('e') != std::string::npos);
	std::cout << std::boolalpha << c << std::endl;
 
	//remove at index
	std::string s = "hello";
	s.erase(s.begin() +4); // or s.erase(4,1);
	std::cout<< s << std::endl;
}

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