Add solution for day 17

AoC2021/code/AoC17.py

@@ -0,0 +1,40 @@
+#!/usr/bin/env python3
+
+import sys, re
+
+def parse(l):
+    return re.compile(r"target area: x=(?P<x1>\d+)..(?P<x2>\d+), y=(?P<y1>-?\d+)..(?P<y2>-?\d+)").search(l)
+
+def step(cx,cy,x,y):
+    cx += x
+    cy += y
+    x = x-1 if x > 0 else (x+1 if x < 0 else 0)
+    y -= 1
+    return cx,cy,x,y
+
+def hits_target(x,y,t):
+    cx, cy, rt, my = 0,0, False, 0
+    while cx <= max(t[0]) and cy >= min(t[1]):
+        cx,cy,x,y = step(cx,cy,x,y)
+        my = max(my,cy)
+        if (min(t[0]) <= cx <= max(t[0])) and (min(t[1]) <= cy <= max(t[1])): rt = True
+    return my, rt
+
+if __name__ == '__main__':
+    x1,x2,y1,y2 = map(int,parse(open(sys.argv[1]).read()).groups())
+    target = ((x1,x2),(y1,y2))
+
+    dic = {}
+    for x in range(target[0][1]+1):
+        for y in range(min(target[1]),target[0][1]+max(map(abs,target[1]))):
+            my,rt = hits_target(x,y,target)
+            if rt: dic[(x,y)] = my
+    
+    # challenge 1
+    res1 = str(max(dic.values()))
+    print("challenge 1:" +"\n" +  res1 + "\n")
+
+    # challenge 2
+    res2 = str(len(dic))
+    print("challenge 2:" +"\n" +  res2 + "\n")
+