day 17

day17-2.py

@@ -0,0 +1,38 @@
+targetx =  (175, 227) #(20, 30)
+targety =  (-134, -79) #(-10, -5)
+
+trajectories = []
+
+class probe:
+    def __init__(self, velo):
+        self.probe_position = (0, 0)
+        self.velocity = velo
+        self.initial_velo = velo
+
+    def steppy(self):
+        while self.probe_position[0] < targetx[1] and self.probe_position[1] > targety[0]:
+            x, y = self.probe_position
+            velox, veloy = self.velocity
+            x += velox
+            y += veloy
+            if x >= targetx[0] and x <= targetx[1] and y <= targety[1] and y >= targety[0]:
+                return self.initial_velo
+            veloy -= 1
+            if velox != 0:
+                if velox < 0:
+                    velox += 1
+                if velox > 0:
+                    velox -= 1
+            self.probe_position = (x, y)
+            self.velocity = (velox, veloy)
+        return None
+
+for yvelo in range(targety[0], 0 - targety[0]):
+    for xvelo in range(1, targetx[1] + 1):
+        prob = probe((xvelo, yvelo))
+        t = prob.steppy()
+        if t is not None:
+            trajectories.append(t)
+        del prob
+
+print(len(trajectories))

day17.py

@@ -0,0 +1,7 @@
+targetx = (175, 227)
+targety = (-134, -79)
+
+y = 0 - targety[0] - 1
+y = (y*y + y)/2
+
+print(y)