This question is not clearly expressed. The question should be like this: start from a certain point on the map, go to the adjacent points (including up, down, left and right of the point), and then go on like this, requiring each point to pass through only once, asking if this road exists?

Here, the point marked 00000000009.

This problem is not the usual one-off problem. Mathematically, the drawing problem is called Euler problem, but the problem of this problem should be called Hamilton problem. Euler problem means that all edges must pass through once from a certain point, which allows points to pass through many times. If there is such a path, it is called Euler path, and Hamilton problem requires all points to pass through once. It doesn't need all the edges to pass through. If there is such a path that passes through all points, it is called Hamilton path, which is essentially different. Euler problem (one-stroke problem) has been completely solved in mathematics, Hamilton problem has not been fully clarified in mathematics, and the necessary and sufficient conditions for the existence of Hamiltonian path have not been found. It is a mathematical problem that has not been solved in mathematics, also called the problem of traveling around the world. This problem can be considered in this way. By reducing to absurdity, if there is a road that passes through all points, it is obvious that the point in the lower left corner of the road must be an endpoint of the road. Mark this point as A (with color A), then mark the point adjacent to it as B (with color B), mark the point adjacent to it as A, and then go forward, so that two adjacent points are marked with different letters (with different colors). Look at that.

A, B, A, B, …, A, B.

That is to say, there are as many points marked A as there are points marked B, but there are not so many points marked A and B, which creates a contradiction, so there is no path through all points.