环城基本移动

(原文) Basic Moves in Loop the City

This game does not require guesses nor the use of complex logic. All you need to do is to follow the 6 moves below:

1. If the number of roads beside a building is already equal to the number marked on the building, cross out the remaining edges
2. If the number of edges that are not crossed out is equal to the number marked on the building, mark the remaining edges with roads
3. If an opening of a road has only one direction, mark that direction with a road
4. Cross out the edges joining the middle of the road
5. If all but one of the remaining edges leading to an intersection is crossed, cross out the remaining edge
6. If marking an edge with a road will form a premature loop, cross that edge out

However, moves 4, 5 and 6 are easily overlooked. Consider an example with the following layout:


Apply move 1:


Apply move 2:


Apply move 3:


Apply move 1:


Apply move 5:


Apply move 2:


Apply moves 1 and 4:


Apply moves 2 and 3:


Apply moves 1 and 4:


Apply moves 2 and 3:


Apply moves 1 and 4:


Apply moves 2 and 3:


Apply moves 1 and 4:


Continue to apply moves 1, 2, 3 and 4:









Continue to apply moves 1, 2, 3 and 4, and you will arrive at:


Apply move 6:


Apply move 3:


Apply move 6:


Apply move 3:


Apply moves 1 and 3 to finish the puzzle: