There are several buildings on the map with size n * n， and a lot of tiles of obstacles that can be destroyed. Suppose I put one soldier on (x,y) of the map, the soldier can reach a building by moving and destroying the obstacles. I need a way to figure out the best choice for the soldier and because there might be a lot of soldiers I hope this process can use as little computing resources as possible. I have come up with path finding and K-D tree finding the nearest neighbor, but neither fits well, since K-D tree works with no obstacles and path-finding needs to traverse a lot building. Besides, the destroying obstacles will affect those have made one path plan.