replaced 1 << 31 - 1 with math.MaxInt32

day03/part1/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"adventofcode/util"
 	"fmt"
+	"math"
 	"strconv"
 	"strings"
 )
@@ -18,9 +19,7 @@ func main() {
 	coordsMap1 := makeCoordinatesMap(split1)
 	coordsMap2 := makeCoordinatesMap(split2)
 
-	// the highest safe int32... https://golang.org/pkg/math/
-	// start this at the highest possible value so it'll be easily overwriteable
-	minDist := 1<<31 - 1
+	minDist := math.MaxInt32
 
 	// iterate over all keys & values in coordsMap1
 	// if that is also in the other map, check if it has a better manhattan dist

day03/part2/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"adventofcode/util"
 	"fmt"
+	"math"
 	"strconv"
 	"strings"
 )
@@ -18,7 +19,7 @@ func main() {
 	coordsMap1 := makeCoordinatesMap(split1)
 	coordsMap2 := makeCoordinatesMap(split2)
 
-	lowestSumOfDistances := 1<<31 - 1
+	lowestSumOfDistances := math.MaxInt32
 
 	// iterate over all keys & values in coordsMap1
 	for key, value1 := range coordsMap1 {

day15/part1/main.go

@@ -12,6 +12,7 @@ import (
 	"adventofcode/util"
 	"fmt"
 	"log"
+	"math"
 	"strconv"
 	"strings"
 )
@@ -398,7 +399,7 @@ removeColsLeft:
 
 // findShortestLength is a (fairly) standard brute force searching algorithm that will return the shortest path from origin to the O2 tank (cell with a 2)
 func findShortestLength(grid [][]int, startX, startY int) int {
-	shortestLength := util.MaxSafeInt
+	shortestLength := math.MaxInt32
 
 	var recurse func(x, y, pathLength int)
 	recurse = func(x, y, pathLength int) {

day18/part1/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"adventofcode/util"
 	"fmt"
+	"math"
 	"strings"
 	"time"
 )
@@ -94,7 +95,7 @@ func MakeDijkstraGrid(grid [][]string, startCoords [2]int) *DijkstraGrid {
 		for col, cellString := range rowSli {
 			finalGrid[row][col] = &dijkstraNode{
 				value:      cellString,
-				distance:   1<<31 - 1,                       // maximum safe integer, effectively 2^31 - 1
+				distance:   math.MaxInt32,
 				keysFound:  map[string]bool{startKey: true}, // initialize with the starting key
 				keysNeeded: make(map[string]bool),           // empty map for now
 				seen:       false,                           // initialize as false
@@ -212,7 +213,7 @@ func (graph *Graph) dfsMinmumDistance() int {
 	// inputs are: 1. the entry point (the key to generate a path FROM)
 	//             2. the keys that have been found so far
 	traverse = func(entry string, keysFound map[string]bool) int {
-		shortestFromThisNode := 1<<31 - 1
+		shortestFromThisNode := math.MaxInt32
 
 		cacheKey := makeCacheKey(entry, keysFound, len(graph.keysToKeys)-1)
 

day18/part2/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"adventofcode/util"
 	"fmt"
+	"math"
 	"sort"
 	"strings"
 )
@@ -100,7 +101,7 @@ func MakeDijkstraGrid(grid [][]string, startCoords [2]int) *DijkstraGrid {
 		for col, cellString := range rowSli {
 			finalGrid[row][col] = &dijkstraNode{
 				value:      cellString,
-				distance:   1<<31 - 1,                       // maximum safe integer, effectively 2^31 - 1
+				distance:   math.MaxInt32,
 				keysFound:  map[string]bool{startKey: true}, // initialize with the starting key
 				keysNeeded: make(map[string]bool),           // empty map for now
 				seen:       false,                           // initialize as false
@@ -223,7 +224,7 @@ func (graph *Graph) dfsMinmumDistance() int {
 	// inputs are: 1. the entry point (the key to generate a path FROM)
 	//             2. the keys that have been found so far
 	traverse = func(entry string, keysFound map[string]bool) int {
-		shortestFromThisNode := 1<<31 - 1
+		shortestFromThisNode := math.MaxInt32
 
 		cacheKey := makeCacheKey(entry, keysFound, graph.allKeysNeeded)
 

day20/part1/main.go

@@ -3,12 +3,10 @@ package main
 import (
 	"adventofcode/util"
 	"fmt"
+	"math"
 	"strings"
 )
 
-// large value to act as "infinite distance away" when setting up a dijkstra grid
-const bigSafeInt = 1 << 30 // 2^30
-
 func main() {
 	input := util.ReadFile("../input.txt")
 	lines := strings.Split(string(input), "\n")
@@ -63,12 +61,12 @@ func MakeDijkstraGrid(inputGrid [][]string) *Dijkstra {
 			// make a node for each cell
 			switch value := inputGrid[row][col]; value {
 			case "#": // wall
-				grid[row-2][col-2] = &Node{"#", bigSafeInt, "", [2]int{0, 0}}
+				grid[row-2][col-2] = &Node{"#", math.MaxInt32, "", [2]int{0, 0}}
 				// if this is a hallway node, use a helper function to determine if there this is a portal
 			case ".": // hallway
 				hallwayNode := &Node{
 					value:           ".",
-					distance:        bigSafeInt,
+					distance:        math.MaxInt32,
 					portalName:      "",
 					jumpCoordinates: [2]int{0, 0},
 				}
@@ -164,7 +162,7 @@ func (dijkstra *Dijkstra) handleFrontOfQueue() (done bool) {
 		isInbounds := nextRow >= 0 && nextRow < len(dijkstra.grid) && nextCol >= 0 && nextCol < len(dijkstra.grid[0])
 		if isInbounds {
 			// if the nextNode is a hallway & has not been traveled to yet
-			if nextNode := dijkstra.grid[nextRow][nextCol]; nextNode != nil && nextNode.value == "." && nextNode.distance == bigSafeInt {
+			if nextNode := dijkstra.grid[nextRow][nextCol]; nextNode != nil && nextNode.value == "." && nextNode.distance == math.MaxInt32 {
 				// update the distance of the nextNode
 				nextNode.distance = currentNode.distance + 1
 				// add its coordinates to the queue

day20/part2/main.go

@@ -6,9 +6,6 @@ import (
 	"strings"
 )
 
-// large value to act as "infinite distance away" when setting up a dijkstra grid
-const bigSafeInt = 1 << 30 // 2^30
-
 func main() {
 	input := util.ReadFile("../input.txt")
 	lines := strings.Split(string(input), "\n")
@@ -144,13 +141,9 @@ func (dijkstra *DijkstraRecursive) AddLayer() (layerCount int) {
 	for row := 0; row < len(sanitizedGrid); row++ {
 		grid[row] = make([]*Node, len(sanitizedGrid[0]))
 		for col := 0; col < len(sanitizedGrid); col++ {
-			switch value := sanitizedGrid[row][col]; value {
-			case "#":
-				grid[row][col] = &Node{"#", bigSafeInt, "", [3]int{0, 0, 0}}
+			switch value := sanitizedGrid[row][col]; value 
 			case ".":
-				grid[row][col] = &Node{
-					value:    ".",
-					distance: bigSafeInt,
+				grid[row][col] = &Node
 				}
 				// get portal name and jump coord from maps if applicable
 				portalName, found := dijkstra.mapCoordsToPortals[[2]int{row, col}]
@@ -198,9 +191,7 @@ func (dijkstra *DijkstraRecursive) handleFrontOfQueue() (done bool) {
 	for i := 0; i < 4; i++ {
 		nextRow, nextCol := row+dRow[i], col+dCol[i]
 		isInbounds := nextRow >= 0 && nextRow < len(currentLayersGrid) && nextCol >= 0 && nextCol < len(currentLayersGrid[0])
-		if isInbounds {
-			// if the nextNode is a hallway & has not been traveled to yet
-			if nextNode := currentLayersGrid[nextRow][nextCol]; nextNode != nil && nextNode.value == "." && nextNode.distance == bigSafeInt {
+		if isInbounds 
 				// update the distance of the nextNode
 				nextNode.distance = currentNode.distance + 1
 				// add its coordinates to the queue, will always be on the same layer b/c this is NOT handling jumps

day24/part1/main.go

@@ -86,7 +86,8 @@ func getBiodiversity(grid [][]string) int {
 	for i, row := range grid {
 		for j, val := range row {
 			// dumb cheeky way to get power of two... 1 is 2^0, then shift the power
-			powerOfTwo := 1 << (5*i + j) // 1 << 0 == 2^0 == 1; 1 << 1 == 2^1
+			// 1 << 0 == 2^0 == 1; 1 << 1 == 2^1
+			powerOfTwo := 1 << (5*i + j)
 			if val == "#" {
 				biodiversity += powerOfTwo
 			}

util/MaxSafeInt.go

@@ -1,3 +0,0 @@
-package util
-
-const MaxSafeInt int = 1<<31 - 1

util/Other.go

@@ -1,12 +0,0 @@
-/*
-just a test to see how building other parts of a package works
-*/
-
-package util
-
-import "fmt"
-
-// OtherFunc is a test :p
-func OtherFunc() {
-	fmt.Println("hello from other func")
-}