Big update: Adding all advent of codes to same repo

AdventOfCode2021/day7/day7.go

@@ -0,0 +1,53 @@
+package day7
+
+import (
+	"fmt"
+	"math"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+func Run(dat []byte) (int, int) {
+	
+	fmt.Println("Day 7")
+	
+	stringDat := strings.Split(string(dat), ",")
+	
+	crabList := make([]int, len(stringDat))
+	for i, value := range stringDat {
+		num, _ := strconv.Atoi(value)
+		crabList[i] = num
+	}
+
+	sort.Ints(crabList)
+
+	median := crabList[len(crabList) / 2]
+
+	lowest := 100000000000
+	part2lowest := 10000000000000
+
+	for i := median - 200; i <= median + 200; i++ {
+
+		difference := 0
+		part2difference := 0
+
+		for _, n := range crabList {
+			currentDifference := math.Abs(float64(i) - float64(n))
+			difference += int(currentDifference)
+			part2difference += int((currentDifference / 2) * (currentDifference + 1))
+		}
+
+		if difference < lowest {
+			lowest = difference
+		}
+
+		if part2difference < part2lowest {
+			part2lowest = part2difference
+		}
+
+	}
+
+	return lowest, part2lowest
+
+}