Merkkijono

#include <iostream>
#include <string>
#include <locale>

int main(int argc, char* argv[])
{
	std::string str;
	std::cin >> str;
	int loop = 1;
	std::locale loc("en-US");

	while(loop)
	{
		loop = 0;
		for(unsigned int i = 0; i < str.length(); i++)
		{
			char current = toupper(str[i]);

			int j;
			for(j = 0; toupper(str[i + j]) == current || !std::isalpha(str[i + j], loc); j++);
			if(j > 1)
			{
				str.erase(i, j);
				loop = 1;
			}
		}
	}

	std::cout << str << std::endl;
}

Test 1

Verdict: RUNTIME ERROR

terminate called after throwing an instance of 'std::runtime_error'
  what():  locale::facet::_S_create_c_locale name not valid

Test 2

Verdict: RUNTIME ERROR

terminate called after throwing an instance of 'std::runtime_error'
  what():  locale::facet::_S_create_c_locale name not valid

Test 3

Verdict: RUNTIME ERROR

terminate called after throwing an instance of 'std::runtime_error'
  what():  locale::facet::_S_create_c_locale name not valid

Test 4

Verdict: RUNTIME ERROR

terminate called after throwing an instance of 'std::runtime_error'
  what():  locale::facet::_S_create_c_locale name not valid

Test 5

Verdict: RUNTIME ERROR

terminate called after throwing an instance of 'std::runtime_error'
  what():  locale::facet::_S_create_c_locale name not valid

Test 6

Verdict: RUNTIME ERROR

terminate called after throwing an instance of 'std::runtime_error'
  what():  locale::facet::_S_create_c_locale name not valid

Test 7

Verdict: RUNTIME ERROR

terminate called after throwing an instance of 'std::runtime_error'
  what():  locale::facet::_S_create_c_locale name not valid

Test 8

Verdict: RUNTIME ERROR

terminate called after throwing an instance of 'std::runtime_error'
  what():  locale::facet::_S_create_c_locale name not valid

Test 9

Verdict: RUNTIME ERROR

terminate called after throwing an instance of 'std::runtime_error'
  what():  locale::facet::_S_create_c_locale name not valid

Test 10

Verdict: RUNTIME ERROR

terminate called after throwing an instance of 'std::runtime_error'
  what():  locale::facet::_S_create_c_locale name not valid