days 7, 8 and 9

7/7.2.go

@@ -0,0 +1,86 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// cat input | go run 7.2.go
+
+type node struct {
+	NodeName    string
+	NodeWeight  int
+	Children    []string
+	ChildWeight int
+}
+
+func main() {
+
+	scanner := bufio.NewScanner(os.Stdin)
+	allNodes := make(map[string]node)
+
+	for scanner.Scan() {
+		s := strings.Split(scanner.Text(), " -> ")
+		var children []string
+
+		if len(s) == 2 {
+			// Node has children
+			children = strings.Split(s[1], ", ")
+		}
+
+		// Name and Weight
+		tNode := strings.Split(s[0], " ")
+		node := node{NodeName: tNode[0]}
+		node.NodeWeight, _ = strconv.Atoi(strings.TrimRight(strings.TrimLeft(tNode[1], "("), ")"))
+		node.Children = children
+		allNodes[node.NodeName] = node
+	}
+
+	for _, n := range allNodes {
+		n.ChildWeight = weighChildren(allNodes, n.NodeName)
+
+	}
+
+	fmt.Println(allNodes)
+
+}
+
+func weighChildren(allNodes map[string]node, child string) int {
+
+	if len(allNodes[child].Children) == 0 {
+		return allNodes[child].NodeWeight
+	}
+
+	sum := allNodes[child].NodeWeight
+	check := 0
+	uneven := false
+
+	for _, e := range allNodes[child].Children {
+
+		r := weighChildren(allNodes, e)
+		sum += r
+
+		if check == 0 {
+			check = r
+		}
+
+		if check != r {
+			uneven = true
+		}
+	}
+
+	f := allNodes[child]
+	f.ChildWeight = sum
+	allNodes[child] = f
+
+	if uneven {
+		for _, e := range allNodes[child].Children {
+			fmt.Println(e, allNodes[e].ChildWeight, allNodes[e].NodeWeight)
+		}
+		os.Exit(0)
+	}
+	return sum
+}

7/7.go

@@ -0,0 +1,83 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// cat input | go run 7.go
+
+type node struct {
+	NodeName   string
+	NodeWeight int
+	Children   []string
+}
+
+func main() {
+
+	scanner := bufio.NewScanner(os.Stdin)
+	allNodes := make(map[string]node)
+
+	for scanner.Scan() {
+
+		s := strings.Split(scanner.Text(), " -> ")
+		var children []string
+
+		if len(s) == 2 {
+			// Node has children
+			children = strings.Split(s[1], ", ")
+		}
+
+		// Name and Weight
+		tNode := strings.Split(s[0], " ")
+		node := node{NodeName: tNode[0]}
+		node.NodeWeight, _ = strconv.Atoi(strings.TrimRight(strings.TrimLeft(tNode[1], "("), ")"))
+		node.Children = children
+
+		fmt.Println(node)
+		allNodes[node.NodeName] = node
+
+	}
+
+	fmt.Println(allNodes)
+
+	// I expect this is going to bite us in part 2, but let's just repeatedly iterate
+	// over the map until all the children are removed. I think this should be quicker
+	// than traversing the tree repeatedly, given we don't know the root node.
+	removed := make(map[string]bool)
+
+	for len(allNodes) > 0 {
+		for k, n := range allNodes {
+			fmt.Println("node:", k)
+			if len(n.Children) == 0 {
+				fmt.Println("removing node", k)
+				removed[k] = true
+				delete(allNodes, k)
+
+			} else {
+
+				if len(allNodes[k].Children) > 0 {
+					c := n.Children[0]
+					if removed[c] == true {
+						fmt.Println("len:", len(allNodes[k].Children))
+						var new []string
+						fmt.Println("nchildren:", n.Children)
+						for j := 0; j < len(n.Children)-1; j++ {
+							fmt.Println("j:", j)
+							new = append(new, n.Children[j+1])
+						}
+						n.Children = new
+						allNodes[k] = n
+
+					}
+				}
+
+			}
+		}
+	}
+	fmt.Println(allNodes)
+
+}