#include <iostream>
#include <string>
 
bool contains( std::string haystack, const std::string& needle ) {
	haystack.insert( 0, " " );
	haystack += ' ';
	auto pos = haystack.find( needle );
 
	if( pos == haystack.npos ) {
		std::cout << "a\n";
		return false;
	}
 
	if( haystack[pos - 1] != ' ' ) {
		std::cout << "b\n";
		return false;
	}
 
	if( haystack[pos + needle.length()] != ' ' ) {
		std::cout << "c\n";
		return false;
	}
 
	return true;
}
 
int main() {
	std::cout << std::boolalpha << contains( "a!hi", "!hi" );
	return 0;
}

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