63 lines
1016 B
Go
63 lines
1016 B
Go
package main
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import (
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"fmt"
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h "git.bullercodeworks.com/brian/adventofcode/helpers"
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)
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// Target Area
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var x1, y1, x2, y2 int
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func main() {
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inp := h.StdinToString()
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fmt.Sscanf(inp, "target area: x=%d..%d, y=%d..%d", &x1, &x2, &y1, &y2)
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var maxy int
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r := make(map[h.Coordinate]bool)
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b := 500
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for x := b * -1; x < b; x++ {
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for y := b * -1; y < b; y++ {
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v := h.Coordinate{X: x, Y: y}
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if m, ok := testForHit(h.Coordinate{}, v); ok {
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if m > maxy {
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maxy = m
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}
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r[v] = true
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}
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}
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}
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fmt.Println("Maximum Peak:", maxy)
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fmt.Println("Valid Velocities:", len(r))
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}
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func testForHit(pos h.Coordinate, vel h.Coordinate) (int, bool) {
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var maxy int
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for {
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pos.X += vel.X
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pos.Y += vel.Y
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if pos.Y > maxy {
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maxy = pos.Y
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}
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if pos.X >= x1 && pos.X <= x2 && pos.Y >= y1 && pos.Y <= y2 {
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return maxy, true
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}
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if vel.X == 0 && vel.Y < y1 {
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return maxy, false
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}
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if vel.X > 0 {
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vel.X--
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}
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if vel.X < 0 {
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vel.X++
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}
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vel.Y--
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}
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}
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type xy struct {
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x int
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y int
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}
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