Initial commit

.gitignore

+exe

Makefile

+
+CXX=g++
+CXX_FLAGS=-Wall -Wextra -pedantic -fsanitize=address
+
+.PHONY: run test clean
+
+exe: main.cpp
+	$(CXX) $(CXX_FLAGS) main.cpp -o exe
+
+run: exe
+	./exe
+
+clean:
+	rm -f ./exe
+
+test: exe
+	for file in test*; do ./exe < $$file; done;
+

main.cpp

+
+#include <iostream>
+
+using namespace std;
+
+//typedef int_fast8_t i8;
+typedef signed short i8;
+
+struct Node {
+	bool has_parent = false;
+	size_t children_size;
+	size_t n_children;
+	Node** children;
+	int index;
+	i8 value;
+	i8 goal;
+};
+
+void add_child(Node& root, Node* child) {
+	if (root.n_children >= root.children_size) {
+		root.children_size += root.children_size / 2;
+		Node** resized = new Node*[root.children_size];
+
+		for (unsigned int i = 0; i < root.n_children; i++) {
+			resized[i] = root.children[i];
+		}
+
+		delete[] root.children;
+		root.children = resized;
+	}
+	
+	child->has_parent = true;
+	root.children[root.n_children++] = child;
+}
+
+Node* new_node(i8 value) {
+	Node* result = new Node();
+
+	result->children_size = 2;
+	result->children = new Node*[2];
+	result->n_children = 0;
+	result->value = value;
+
+	return result;
+}
+
+void load_input(Node*** nodes, Node& root, int& n) {
+	cin >> n;
+
+	*nodes = new Node*[n];
+
+	for (int i = 0; i < n; i++) {
+		(*nodes)[i] = new_node(0);
+		(*nodes)[i]->index = i;
+	}
+
+	//cout << "Dear Evan Hansen," << endl;
+
+	for (int i = 0; i < n - 1; i++) {
+		int u, v;
+		cin >> u >> v;
+
+		if (u > v) {
+			int tmp = u;
+			u = v;
+			v = tmp;
+		}
+
+		add_child(*(*nodes)[u - 1], (*nodes)[v - 1]);
+	}
+
+	//cout << "today is gonna be a good day," << endl;
+
+	for (int i = 0; i < n; i++) {
+		i8 init;
+		cin >> init;
+
+		(*nodes)[i]->value = init;
+	}
+
+	//cout << "and here's why:" << endl;
+
+	for (int i = 0; i < n; i++) {
+		i8 goal;
+		cin >> goal;
+
+		(*nodes)[i]->goal = goal;
+	}
+	
+	for (int i = 0; i < n; i++) {
+		if (!(*nodes)[i]->has_parent) {
+			root = *(*nodes)[i];
+			break;
+		}
+	}
+}
+
+void print_tree(Node& root) {
+	cout << "{ " << root.value << "; children = [";
+
+	for (unsigned int i = 0; i < root.n_children; i++) {
+		print_tree(*(root.children[i]));
+	}
+
+	cout << "]; }";
+}
+
+void add_step(Node& root, int** steps, int& steps_size, int& n_steps) {
+	if (n_steps >= steps_size - 1) {
+		steps_size += steps_size / 2;
+		int* resized = new int[steps_size];
+
+		for (int i = 0; i < n_steps; i++) {
+			resized[i] = (*steps)[i];
+		}
+
+		delete[] *steps;
+		*steps = resized;
+	}
+
+	(*steps)[n_steps++] = root.index;
+}
+
+void xor_xor_xoooor(Node& root, int** steps, int& steps_size, int& n_steps, i8 n_flips = 0, i8 n_other_flips = 0) {
+	//cout << "processing " << root.index << ", v=" << root.value << ", g=" << root.goal << ", flips=" << (int)n_flips << endl;
+
+	if ((root.value != root.goal && n_flips == 0) || (root.value == root.goal && n_flips != 0)) {
+		//cout << "\tflipping!" << endl;
+		add_step(root, steps, steps_size, n_steps);
+		root.value = !root.value;
+		
+		n_flips++;
+	}
+
+	n_flips %= 2;
+
+	cout << root.index + 1 << ": " << root.value << " " << endl;
+
+	for (unsigned int i = 0; i < root.n_children; i++) {
+		xor_xor_xoooor(*root.children[i], steps, steps_size, n_steps, n_other_flips, n_flips);
+	}
+}
+
+int main() {
+	int* steps = new int[2];
+	int steps_size = 2;
+	int n_steps = 0;
+	Node** nodes;
+	Node root;
+	int n;
+
+	load_input(&nodes, root, n);
+	//print_tree(root);
+	//cout << endl;
+
+	xor_xor_xoooor(root, &steps, steps_size, n_steps);
+
+	cout << n_steps << endl;
+	for (int i = 0; i < n_steps; i++) {
+		cout << steps[i] + 1 << endl;
+	}
+
+	delete[] steps;
+
+	for (int i = 0; i < n; i++) {
+		delete[] nodes[i]->children;
+		delete nodes[i];
+	}
+
+	delete[] nodes;
+
+	return 0;
+}
+

test00

+1
+0
+1

test01

+2
+1 2
+0 0
+1 1

test02

+5
+1 2
+2 3
+3 4
+4 5
+0 0 0 0 0
+1 1 1 1 1
+

test03

+10
+2 1
+3 1
+4 2
+5 1
+6 2
+7 5
+8 6
+9 8
+10 5
+1 0 1 1 0 1 0 1 0 1
+1 0 1 0 0 1 1 1 0 1

test04

+5
+1 2
+1 3
+3 4
+3 5
+0 0 1 1 0
+1 1 1 1 1
+

test05

+3
+1 2
+2 3
+0 0 0
+0 0 0

test06

+5
+1 2
+2 3
+3 4
+4 5
+1 1 1 1 0
+0 0 1 1 0

test07

+5
+1 2
+1 3
+1 4
+1 5
+0 1 1 0 0
+1 0 1 0 1