rotation

Makefile

.PHONY: clean all

CPPFLAGS = -std=c++14
LINK.o = $(LINK.cc)

all: rotation

clean:
	rm *.o rotation

rotation: rotation.o

rotation.cpp

#include <string_view>
#include <iostream>

bool strings_are_rotations(std::string_view a, std::string_view b) {
	size_t size = a.size();
	if (size != b.size())
		return false;
	for (size_t i = 0; i < size; i++) {
		for (size_t j = 0; ; j++) {
			if (j == size)
				return true;
			if (a[j] != b[(i+j) % size])
				break;
		}
	}
	return false;
}

void print_strings_are_rotations(std::string_view a, std::string_view b) {
	std::cerr << a << (strings_are_rotations(a, b) ? " is a rotation of " : " is not a rotation of ") << b << std::endl;
}

int main() {
	print_strings_are_rotations("foobar", "banana");
	print_strings_are_rotations("foobar", "notafoo");
	print_strings_are_rotations("foobar", "foobar");
	print_strings_are_rotations("foobar", "barfoo");
	print_strings_are_rotations("aaaab", "aabaa");
	return 0;
}