Now that you have a ball of radius r, you want it to go from the bottom boundary of the map to the top boundary of the map . But there are a lot of little spikes in the map, and we can think of them as points. Your ball can't touch any of the points and the left or the right boundary of the map, even if the edge of the ball can't touch them. The area of the map can be seen as 100×100100 times 100100×100, with the lower left corner (0,0)and the upper right corner . The bottom boundary is y = 0, and the top boundary is y = 100.
Now that you have a ball of radius r, you want it to go from the bottom boundary of the map to the top boundary of the map (starting and ending points can be considered outside the map, entering the map from the bottom boundary and leaving the map from the top boundary). But there are a lot of little spikes in the map, and we can think of them as points. Your ball can't touch any of the points and the left or the right boundary of the map, even if the edge of the ball can't touch them. The area of the map can be seen as 100×100100 times 100100×100, with the lower left corner (0,0)and the upper right corner (100,100). The bottom boundary is y = 0, and the top boundary is y = 100.
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