Here's a puzzler for you.

I'm designing continuous terrain exploration by dynamically loading/unloading 100x100 blocks of tiles.

Given the following coordinates (same for x or y-axis):

1
| ...|-300 ... -201|-200 ... -101|-100 ... -1|0 ... 99|100 ... 199|200 ... 299|... |

Can you come up with a simple function that given an int, returns the anchor point? The anchor point is the left-hand number in the range and is a multiple of 100. For example for any value between -200 ... -101 return -200. For 100 ... 199 return 100.

The biggest problem for me is that integer division of negative values seems to be different from language to language! (-1 / 100) gives me -1 in python but 0 in Java.

Otherwise I'd use f(x) = x / 100 * 100