From 92a9400eefc059915de3f6ccc6d617669b4a6648 Mon Sep 17 00:00:00 2001
From: Luke Else <mail@luke-else.co.uk>
Date: Sat, 4 Dec 2021 22:42:13 +0000
Subject: [PATCH] day 4b complete

---
 day4/day 4b/Board.go  |  16 +++++
 day4/day 4b/go.mod    |   3 +
 day4/day 4b/main.go   | 162 ++++++++++++++++++++++++++++++++++++++++++
 day4/day 4b/testInput |  19 +++++
 4 files changed, 200 insertions(+)
 create mode 100644 day4/day 4b/Board.go
 create mode 100644 day4/day 4b/go.mod
 create mode 100644 day4/day 4b/main.go
 create mode 100644 day4/day 4b/testInput

diff --git a/day4/day 4b/Board.go b/day4/day 4b/Board.go
new file mode 100644
index 0000000..4210456
--- /dev/null
+++ b/day4/day 4b/Board.go	
@@ -0,0 +1,16 @@
+package main
+
+type Board struct {
+	Values [5][5]boardValue
+	Hash   map[int]location
+}
+
+type boardValue struct {
+	Value   int
+	Visited bool
+}
+
+type location struct {
+	x int
+	y int
+}
diff --git a/day4/day 4b/go.mod b/day4/day 4b/go.mod
new file mode 100644
index 0000000..e938e2e
--- /dev/null
+++ b/day4/day 4b/go.mod	
@@ -0,0 +1,3 @@
+module PWD
+
+go 1.17
diff --git a/day4/day 4b/main.go b/day4/day 4b/main.go
new file mode 100644
index 0000000..83cce5e
--- /dev/null
+++ b/day4/day 4b/main.go	
@@ -0,0 +1,162 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+func main() {
+	content := returnContent("../input")
+	//content := returnContent("testInput")
+	boards, nums := loadBoards(content)
+	fmt.Println(run(boards, nums))
+}
+
+func run(boards *[]Board, nums []int) int {
+	var completedBoards map[*Board]bool = make(map[*Board]bool)
+	var bingo []int
+	var n int
+	for i := 0; i < len(nums); i++ {
+		bingo = callNumber(nums[i], boards)
+
+		for X := 0; X < len(bingo); X++ {
+			_, present := completedBoards[&(*boards)[bingo[X]]]
+			if !present {
+				n = nums[i]
+				fmt.Println("found value", bingo, n, returnAnswer(&(*boards)[bingo[X]], n))
+			}
+			completedBoards[&(*boards)[bingo[X]]] = true
+		}
+
+	}
+
+	//return the answer
+	return returnAnswer(&(*boards)[bingo[0]], n)
+}
+
+func loadBoards(content *[]string) (boards *[]Board, nums []int) {
+	boards = new([]Board)
+	newBoard := Board{
+		Hash: make(map[int]location, 25),
+	}
+	boardNum := 0
+	row := 0
+
+	for i := 0; i < len(*content); i++ {
+
+		if i == 0 {
+			//add nums
+			numlist := strings.Split((*content)[i], ",")
+
+			for i := 0; i < len(numlist); i++ {
+				num, _ := strconv.Atoi(numlist[i])
+				nums = append(nums, num)
+			}
+
+			i++
+		} else {
+
+			if (*content)[i] != "" {
+
+				regex := regexp.MustCompile("([0-9]+)")
+				values := regex.FindAllString((*content)[i], 5)
+
+				for j := 0; j < len(values); j++ {
+					value, _ := strconv.Atoi(values[j])
+					newBoard.Values[row][j] = boardValue{Value: value, Visited: false}
+					newBoard.Hash[value] = location{x: row, y: j}
+				}
+				row++
+
+				if row == 5 {
+					boardNum++
+					i++
+					*boards = append(*boards, newBoard)
+					newBoard = Board{
+						Hash: make(map[int]location, 25),
+					}
+					row = 0
+				}
+
+			}
+
+		}
+
+	}
+	return
+}
+
+func callNumber(n int, boards *[]Board) (cards []int) {
+	for i := 0; i < len(*boards); i++ {
+		location, present := (*boards)[i].Hash[n]
+		if present {
+			//Change the value to visited
+			(*boards)[i].Values[location.x][location.y].Visited = true
+			if checkBingo(&(*boards)[i], location.x, location.y) {
+				cards = append(cards, i)
+			}
+		}
+	}
+	return
+}
+
+func checkBingo(board *Board, x int, y int) bool {
+	checkVertical := true
+	//check if bingo for a given row and column
+
+	//Check row
+	for i := 0; i < 5; i++ {
+		if !(*board).Values[x][i].Visited {
+			checkVertical = false
+			break
+		}
+	}
+
+	checkHorizontal := true
+	//Check column
+	for i := 0; i < 5; i++ {
+		if !(*board).Values[i][y].Visited {
+			checkHorizontal = false
+			break
+		}
+	}
+
+	return (checkVertical || checkHorizontal)
+}
+
+func returnAnswer(board *Board, n int) (answer int) {
+	for i := 0; i < 5; i++ {
+		for j := 0; j < 5; j++ {
+			if !(*board).Values[i][j].Visited {
+				answer += (*board).Values[i][j].Value
+			}
+		}
+	}
+
+	answer = answer * n
+	return
+}
+
+func returnContent(path string) *[]string {
+	//read file and return it as an array of integers
+
+	file, err := os.Open(path)
+	var content []string
+
+	if err != nil {
+		fmt.Println("Unlucky, the file didn't open")
+		return &content
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		content = append(content, scanner.Text())
+	}
+
+	return &content
+}
diff --git a/day4/day 4b/testInput b/day4/day 4b/testInput
new file mode 100644
index 0000000..49d17bc
--- /dev/null
+++ b/day4/day 4b/testInput	
@@ -0,0 +1,19 @@
+7,4,9,5,11,17,23,2,0,14,21,24,10,16,13,6,15,25,12,22,18,20,8,19,3,26,1
+
+22 13 17 11  0
+ 8  2 23  4 24
+21  9 14 16  7
+ 6 10  3 18  5
+ 1 12 20 15 19
+
+ 3 15  0  2 22
+ 9 18 13 17  5
+19  8  7 25 23
+20 11 10 24  4
+14 21 16 12  6
+
+14 21 17 24  4
+10 16 15  9 19
+18  8 23 26 20
+22 11 13  6  5
+ 2  0 12  3  7
\ No newline at end of file