P1238 Maze Pathfinding

There is an $m \times n$ grid maze (meaning $m$ rows and $n$ columns), with some cells passable and others not. Use $1$ for passable and $0$ for impassable. The input provides these $m \times n$ values and the start and end points (each point is described by two numbers: its row index and column index). Your task is to write a program to find all feasible paths such that no cell is visited more than once, and movement is allowed only in the four directions: up, down, left, and right. If no path is feasible, output the corresponding information ($-1$ means no path). Priority order: left, up, right, down. **The testdata are guaranteed to be randomly generated.**

The first line contains two integers $m, n$ ($1 < m, n < 15$). Then follow $m$ rows and $n$ columns of data consisting of $1$ and $0$. The last two lines are the start point and the end point.

Output all feasible paths. When describing a point, use the form $(x, y)$. Except for the starting point, connect consecutive points using `->` to indicate direction. If there is no feasible path, output $-1$.

The testdata are guaranteed to be randomly generated. In fact, if $n = m = 14$ and every cell is $1$, there are $69450664761521361664274701548907358996488$ paths. Translated by ChatGPT 5