advent: day9 part 1

vtech6 · vtech6 · commit ebf22242f1dc · 2022-12-15T10:56:54.000+01:00
diff --git a/advent/day9/day9.go b/advent/day9/day9.go
@@ -11,8 +11,13 @@ import (
 )
 
 func Solve() {
+
+	testInput := strings.Split("R 1,U 1,L 2,D 2,R 2,U 2,L 1,D 1", ",")
+	drawMap(testInput)
+	testInput2 := strings.Split("R 4,U 4,L 3,D 1,R 4,D 1,L 5,R 2", ",")
+	drawMap(testInput2)
+
 	input := advent.ReadInput("day9")
-	// testInput := strings.Split("R 1,U 1,L 2,D 2,R 2,U 2,L 1,D 1", ",")
 	splitInput := input.Split("\n")
 	drawMap(splitInput)
 }
@@ -33,7 +38,6 @@ func drawMap(input []string) {
 	xAxis := 0
 	xAxisMax := 0
 	xAxisMin := 0
-
 	headMap := SnakeMap{positions: []positions{}}
 	snekMap := SnakeMap{positions: []positions{}}
 	for _, row := range input {
@@ -47,7 +51,6 @@ func drawMap(input []string) {
 			if yAxis < yAxisMin {
 				yAxisMin = yAxis
 			}
-
 		}
 		if splitRow[0] == "U" {
 			for step := 0; step < conv; step++ {
@@ -77,12 +80,8 @@ func drawMap(input []string) {
 			}
 		}
 	}
-	fmt.Printf("X: %v, Xmin: %v, Xmax: %v, Y: %v, Ymin: %v, Ymax: %v\n", xAxis, xAxisMin, xAxisMax, yAxis, yAxisMin, yAxisMax)
-	fmt.Println(headMap.positions)
 	drawTail(headMap.positions, &snekMap)
-	fmt.Println(snekMap.positions)
-	fmt.Printf("Unique positions for input: %v, snake: %v\n", len(lo.Uniq(headMap.positions)), len(lo.Uniq(snekMap.positions)))
-
+	fmt.Printf("Unique positions for head: %v, tail: %v\n", len(lo.Uniq(headMap.positions)), len(lo.Uniq(snekMap.positions)))
 }
 func (snakeMap *SnakeMap) addPosition(xValue int, yValue int) {
 	position := positions{x: xValue, y: yValue}
@@ -92,17 +91,15 @@ func drawTail(headPositions []positions, snekMap *SnakeMap) {
 	snekMap.positions = []positions{{x: 0, y: 0}, {x: 0, y: 0}}
 	for posIndex, position := range headPositions {
 		if posIndex > 1 {
-			tailPosition := headPositions[posIndex-2]
 			prevPosition := headPositions[posIndex-1]
-			pointDiff := float64(position.x - tailPosition.x + position.y - tailPosition.y)
-			pointDiff2 := float64(position.x - snekMap.positions[posIndex-1].x + position.y - snekMap.positions[posIndex-1].y)
-
-			if posIndex > 4 {
-				fmt.Printf("PointDiff: %v, PointDiff2: %v, Pos: %v, Snake: %v\n", pointDiff, pointDiff2, position, snekMap.positions[posIndex-1])
-			}
-			if math.Abs(pointDiff) > 1 && math.Abs(pointDiff2) > 0 {
-				bothAx := position.x != tailPosition.x && position.y != tailPosition.y
-				if bothAx {
+			xAx := math.Abs(float64(position.x - snekMap.positions[posIndex-1].x))
+			yAx := math.Abs(float64(position.y - snekMap.positions[posIndex-1].y))
+			// distance := math.Abs(float64(position.x - tailPosition.x + position.y - tailPosition.y))
+			if xAx+yAx >= 2 {
+				bothAx := position.x != snekMap.positions[posIndex-1].x && position.y != snekMap.positions[posIndex-1].y
+				if xAx+yAx >= 3 {
+					snekMap.positions = append(snekMap.positions, prevPosition)
+				} else if bothAx {
 					snekMap.positions = append(snekMap.positions, snekMap.positions[posIndex-1])
 				} else {
 					snekMap.positions = append(snekMap.positions, prevPosition)
@@ -113,12 +110,3 @@ func drawTail(headPositions []positions, snekMap *SnakeMap) {
 		}
 	}
 }
-
-// [{0 0} {0 -1} {0 -2} {1 -2} {2 -2} {2 -3} {2 -2} {1 -2} {0 -2} {0 -1} {0  0} {0 -1}]
-// [{0 0} {0  0} {0 -1} {0 -1} {1 -2} {1 -2} {1 -2} {1 -2} {1 -2} {1 -2} {0 -1} {0 -1}]
-
-// [{0 0} {1 0} {1 1} {0 1} {-1 1} {-1 0} {-1 -1} {0 -1} {1 -1} {1  0} {1 1} {0 1}]
-// [{0 0} {0 0} {0 0} {0 0} { 0 0} { 0 0} {-1  0} {-1 0} {0 -1} {0 -1} {1 0} {1 0}]
-
-// {3 4} {2 4} {1 4} {1 3} {2 3} {3 3} {4 3}
-// {4 3} {3 4} {2 4} {2 4} {2 4} {2 4} {3 3}
