Started day 25 puzzle

day25/day25.go

@@ -0,0 +1,190 @@
+package day25
+
+import (
+	"fmt"
+	"strings"
+
+	"gitea.paas.celticinfo.fr/oabrivard/aoc2023/utils"
+)
+
+type Graph map[string]map[string]bool
+type Edge struct {
+	left  string
+	right string
+}
+
+func buildGraph(lines []string) Graph {
+	graph := map[string]map[string]bool{}
+
+	for _, line := range lines {
+		parts := strings.Split(line, ":")
+
+		src := parts[0]
+		if _, found := graph[src]; !found {
+			graph[src] = map[string]bool{}
+		}
+		links := graph[src]
+
+		dests := strings.Fields(strings.TrimSpace(parts[1]))
+		for _, dst := range dests {
+			links[dst] = true
+
+			if _, found := graph[dst]; !found {
+				graph[dst] = map[string]bool{}
+			}
+			reverseLink := graph[dst]
+			reverseLink[src] = true
+		}
+	}
+
+	return graph
+}
+
+func printGraph(graph Graph) {
+	for k1, v1 := range graph {
+		fmt.Print(k1, ": ")
+		for k2 := range v1 {
+			fmt.Print(k2, " ")
+		}
+		fmt.Println("")
+	}
+}
+
+func countComponents(graph Graph) int {
+	visited := map[string]bool{}
+	count := 0
+
+	for node := range graph {
+		if !visited[node] {
+			count++
+			queue := utils.NewQueue[string]()
+			queue.Enqueue(node)
+
+			for queue.HasElement() {
+				curNode := queue.Dequeue()
+				visited[curNode] = true
+
+				for linkedNode := range graph[curNode] {
+					if !visited[linkedNode] {
+						queue.Enqueue(linkedNode)
+					}
+				}
+			}
+		}
+	}
+	return count
+}
+
+func buildVerticesLists(graph Graph) []map[string]bool {
+	visited := map[string]bool{}
+	result := []map[string]bool{}
+	currSubgraph := 0
+
+	for node := range graph {
+		if !visited[node] {
+			result = append(result, map[string]bool{})
+			result[currSubgraph][node] = true
+
+			queue := utils.NewQueue[string]()
+			queue.Enqueue(node)
+
+			for queue.HasElement() {
+				curNode := queue.Dequeue()
+				visited[curNode] = true
+				result[currSubgraph][curNode] = true
+
+				for linkedNode := range graph[curNode] {
+					if !visited[linkedNode] {
+						queue.Enqueue(linkedNode)
+					}
+				}
+			}
+			currSubgraph++
+		}
+	}
+	return result
+}
+
+func buildEdgeList(graph Graph) []Edge {
+	edges := map[Edge]bool{}
+
+	for node, connectedNodes := range graph {
+		for connectedNode := range connectedNodes {
+			_, found1 := edges[Edge{node, connectedNode}]
+			_, found2 := edges[Edge{connectedNode, node}]
+
+			if !found1 && !found2 {
+				edges[Edge{node, connectedNode}] = true
+			}
+		}
+	}
+
+	result := []Edge{}
+	for e := range edges {
+		result = append(result, e)
+	}
+	return result
+}
+
+func findEdgesToDelete(graph Graph, edges []Edge) (bool, *Edge, *Edge, *Edge) {
+	for i := 0; i < len(edges); i++ {
+		for j := i + 1; j < len(edges); j++ {
+			for k := j + 1; k < len(edges); k++ {
+				// Delete edges i, j and k from graph
+				delete(graph[edges[i].left], edges[i].right)
+				delete(graph[edges[i].right], edges[i].left)
+				delete(graph[edges[j].left], edges[j].right)
+				delete(graph[edges[j].right], edges[j].left)
+				delete(graph[edges[k].left], edges[k].right)
+				delete(graph[edges[k].right], edges[k].left)
+
+				// count components
+				count := countComponents(graph)
+
+				// restore Graph
+				graph[edges[i].left][edges[i].right] = true
+				graph[edges[i].right][edges[i].left] = true
+				graph[edges[j].left][edges[j].right] = true
+				graph[edges[j].right][edges[j].left] = true
+				graph[edges[k].left][edges[k].right] = true
+				graph[edges[k].right][edges[k].left] = true
+
+				if count == 2 {
+					return true, &edges[i], &edges[j], &edges[k]
+				}
+			}
+		}
+	}
+
+	return false, nil, nil, nil
+}
+
+func Part1(lines []string) int {
+	graph := buildGraph(lines)
+	printGraph(graph)
+	edges := buildEdgeList(graph)
+	fmt.Println(edges)
+	success, edge1, edge2, edge3 := findEdgesToDelete(graph, edges)
+
+	if !success {
+		return 0
+	}
+
+	fmt.Println(*edge1)
+	fmt.Println(*edge2)
+	fmt.Println(*edge3)
+
+	delete(graph[edge1.left], edge1.right)
+	delete(graph[edge1.right], edge1.left)
+	delete(graph[edge2.left], edge2.right)
+	delete(graph[edge2.right], edge2.left)
+	delete(graph[edge3.left], edge3.right)
+	delete(graph[edge3.right], edge3.left)
+
+	result := buildVerticesLists(graph)
+
+	fmt.Println(result[0])
+	fmt.Println(result[1])
+
+	return len(result[0]) * len(result[1])
+}

day25/day25_test.go

@@ -0,0 +1,41 @@
+package day25
+
+import (
+	"testing"
+
+	"gitea.paas.celticinfo.fr/oabrivard/aoc2023/utils"
+)
+
+func TestPart1(t *testing.T) {
+	lines := []string{
+		"jqt: rhn xhk nvd",
+		"rsh: frs pzl lsr",
+		"xhk: hfx",
+		"cmg: qnr nvd lhk bvb",
+		"rhn: xhk bvb hfx",
+		"bvb: xhk hfx",
+		"pzl: lsr hfx nvd",
+		"qnr: nvd",
+		"ntq: jqt hfx bvb xhk",
+		"nvd: lhk",
+		"lsr: lhk",
+		"rzs: qnr cmg lsr rsh",
+		"frs: qnr lhk lsr",
+	}
+
+	result := Part1(lines)
+
+	if result != 54 {
+		t.Fatalf("expected 54, got %d", result)
+	}
+}
+
+func TestPart1WithInput(t *testing.T) {
+	lines := utils.ReadLines("input.txt")
+
+	result := Part1(lines)
+
+	if result != 2402 {
+		t.Fatalf("expected 2402, got %d", result)
+	}
+}