#include <stdio.h>

char switch_cases_1_tab[256] = {
	['a' ... 'z' ] = 'A' - 'a',
	['A' ... 'Z' ] = 'a' - 'A',
};

char switch_cases_1(char ch)
{
	return ch + switch_cases_1_tab[(unsigned char)ch];
}

char switch_cases_2(char ch)
{
	switch (ch) {
		case 'A' ... 'Z':
			return ch + ('a' - 'A');
		case 'a' ... 'z':
			return ch + ('A' - 'a');
		default:
			return ch;
	}
}

int main()
{
	char demo[] = "This Is A Simple Test.\n";
	int i;

	printf("%s", demo);
	for (i=0; demo[i]; i++) demo[i] = switch_cases_1(demo[i]);
	printf("%s", demo);
	for (i=0; demo[i]; i++) demo[i] = switch_cases_2(demo[i]);
	printf("%s", demo);

	return 0;
}