const rl = require("readline").createInterface({ input: process.stdin }); var iter = rl[Symbol.asyncIterator](); const readline = async () => (await iter.next()).value; let arr = []; let N, M; // 记录当前路线下访问过的点 let viewed = new Set(); let direction = [ [1, 0], [0, 1], [-1, 0], [0, -1], ]; let endIn...