C++ (Cpp) States::find Examples

Example #1

File: dfa_converter.cpp Project: LelouchHe/mpl

// 所有能从from通过EPSILON能达到的NFA状态(包括from)
static States fill(const std::vector<NFATran>& trans, const States& last, const States& from, bool* is_last) {
	std::queue<int> q;
	for (States::const_iterator it = from.begin();
			it != from.end(); ++it) {
		q.push(*it);
	}

	// ends表示终点(即最终状态),要判断这次转移是否只有-1
	States ends;
	States to;
	while (!q.empty()) {
		int s = q.front();
		q.pop();

		to.insert(s);
		if (last.find(s) != last.end()) {
			*is_last = true;
		}

		if (s == -1) {
			ends.insert(-1);
			continue;
		}

		const NFATran& tran = trans[s];
		NFATran::const_iterator it = tran.find(EPSILON);
		if (it == tran.end()) {
			ends.insert(s);
			continue;
		}

		const States& next = it->second;
		for (States::const_iterator nit = next.begin();
				nit != next.end(); ++nit) {
			if (to.find(*nit) == to.end()) {
				q.push(*nit);
			}
		}
	}

	if (ends.find(-1) == ends.end() || ends.size() > 1) {
		to.erase(-1);
	} else {
		to.clear();
		to.insert(-1);
	}

	return to;
}