Big update: Adding all advent of codes to same repo

AdventOfCode2021/day3/day3.go

@@ -0,0 +1,101 @@
+package day3
+
+import (
+	"bytes"
+)
+
+func Run(dat []byte) (int, int) {
+  
+  lines := bytes.Split(dat, []byte("\n"))
+  lineLength := len(lines[0])
+
+  commonMap := make(map[int]int)
+
+  for _, line := range lines {
+
+    splitLine := bytes.Split(line, []byte(""))
+    
+    for i := 0; i < len(splitLine); i++ {
+
+      //Negative means that 0 is more common
+      if splitLine[i][0] == 0x31 {
+        commonMap[i] = commonMap[i] - 1
+      } else {
+        commonMap[i] = commonMap[i] + 1 
+      }
+
+    }
+    
+  }
+
+  gamma := 0
+  epsilon := 0
+
+  for key, value := range commonMap {
+    if value > 0 {
+      gamma += intExponent(2, lineLength - key - 1)
+    } else {
+      epsilon += intExponent(2, lineLength - key - 1)
+    }
+  }
+
+  return gamma * epsilon, part2(lines[:len(lines) - 1], true, 0) * 
+                          part2(lines[:len(lines) - 1], false, 0)
+
+}
+
+func part2(givenLines [][]byte, higher bool, checkPosition int) int {
+
+  if len(givenLines) == 1 {
+    returnValue := 0
+    
+    for i := len(givenLines[0]) - 1; i >= 0; i-- {
+
+      if givenLines[0][len(givenLines[0]) - 1 - i] == 0x31 {
+        returnValue += intExponent(2, i)
+      }
+
+    }
+    return returnValue
+  } else {
+    
+    oneLines := make([][]byte, 0)
+    zeroLines := make([][]byte, 0)
+
+    for _, line := range givenLines {
+      if line[checkPosition] == 0x31 {
+        oneLines = append(oneLines, line)
+      } else {
+        zeroLines = append(zeroLines, line)
+      }
+    }
+    
+    if higher {
+
+      if len(oneLines) >= len(zeroLines) {
+        return part2(oneLines, higher, checkPosition + 1)
+      } else if len(oneLines) < len(zeroLines) {
+        return part2(zeroLines, higher, checkPosition + 1)
+      }
+
+    } else {
+      
+      if len(oneLines) >= len(zeroLines) {
+        return part2(zeroLines, higher, checkPosition + 1)
+      } else if len(oneLines) < len(zeroLines) {
+        return part2(oneLines, higher, checkPosition + 1)
+      }
+
+    }
+
+  }
+  return 0
+}
+
+func intExponent(base int, power int) int {
+  result := 1
+  for i := 1; i <= power; i++ {
+    result *= base
+  }
+  return result
+}