Solution for Problem 17

p17a.py

@@ -0,0 +1,71 @@
+# https://adventofcode.com/2021/day/17 part 1
+# Created by: Menaka S. 17 Dec 2021
+
+import sys
+import binascii
+
+line = sys.stdin.read()
+line = line.strip()
+parts = line.split('=')
+parts[1] = parts[1].split(', ')[0]
+tx =parts[1].split('..')
+ty =parts[2].split('..')
+tstartx = int(tx[0])
+tendx = int(tx[1])
+tstarty = int(ty[0])
+tendy = int(ty[1])
+if tstartx > tendx:
+	temp = tstartx
+	tstartx = tendx
+	tendx = temp
+if tstarty > tendx:
+	temp = tstarty
+	tstarty = tendx
+	tendy = temp
+#print(tstartx,tendx,tstarty,tendy)
+
+
+maxy = -1000
+maxsteps = 800
+
+def is_in_target(x,y):
+	global tstartx, tstarty, tendx, tendy
+	if tstartx <= x <= tendx and tstarty <= y <= tendy:
+		return 1
+	return 0
+
+
+def calctrajectory(x,y,i,j,step):
+	global currentmax, intarget
+	if step >= maxsteps:
+		return
+	x += i
+	y += j
+	if i > 0:
+		i -= 1
+	elif i < 0:
+		i += 1 
+	j -= 1
+	if y > currentmax:
+		currentmax = y
+	step += 1
+	if is_in_target(x,y):
+		intarget = 1
+		#print(x,y,i,j,step)
+		#print("....In target")
+	calctrajectory(x,y,i,j,step)
+
+mx = 100
+for i in range(-mx,mx):
+	for j in range(-mx,mx):
+		currentmax = -1000
+		intarget = 0
+		calctrajectory(0,0,i,j,0)
+		if currentmax > maxy and intarget:
+			maxy = currentmax
+			ivx = i
+			ivy = j
+
+print(maxy) #,ivx,ivy)
+
+

p17b.py

@@ -0,0 +1,46 @@
+# https://adventofcode.com/2021/day/17 part 2
+# Created by: Menaka S. 17 Dec 2021
+
+#Slow code; Need to work on performance
+
+import sys
+
+line = sys.stdin.read().strip()
+parts = line.split('=')
+parts[1] = parts[1].split(', ')[0]
+tx =parts[1].split('..')
+ty =parts[2].split('..')
+tstartx = int(tx[0])
+tendx = int(tx[1])
+tstarty = int(ty[0])
+tendy = int(ty[1])
+if tstartx > tendx:
+	tstartx, tendx = tendx, tstartx
+if tstarty > tendx:
+	tstarty, tendy = tendy, tstarty
+
+maxsteps = 500
+ivs = set()
+
+def calctrajectory(x,y,i,j,step):
+	while step <= maxsteps:
+		x += i
+		y += j
+		if i > 0:
+			i -= 1
+		elif i < 0:
+			i += 1 
+		j -= 1
+		step += 1
+		if tstartx <= x <= tendx and tstarty <= y <= tendy:
+			return 1
+
+mx = 300
+for i in range(-mx,mx):
+	for j in range(-mx,mx):
+		if calctrajectory(0,0,i,j,0):
+			ivs.add((i,j))
+
+print(len(ivs))
+
+