✏️ 一笔画One-Stroke Drawing
在线一笔画闯关游戏：从一个点出发，沿着线条把整幅图一笔画完，每条线只能走一次、不能抬笔。手指或鼠标按住拖动就能连线，关卡越往后线条越多、越复杂。支持撤销、重来和提示，自动保存闯关进度，手机电脑都能玩。One-stroke drawing puzzle online: start from a dot and trace the whole figure in a single stroke, using every line exactly once without lifting your finger. Press and drag to draw; later levels have more and trickier lines. Undo, restart and hints are built in and your level progress is saved.
按住一个点，沿着灰色线条拖到相邻的点；也可以依次点击。Z 撤销一步，H 提示。Press a dot and drag along the grey lines to the next dot, or tap dots one by one. Z undoes a step and H gives a hint.
玩法说明与常见问题How to play & FAQ
「一笔画」怎么玩？How do I play One-Stroke Drawing?
这就是数学里的“欧拉路径”问题：数一数每个点连着几条线，连着奇数条线的点叫奇点。如果图里有两个奇点，就必须从其中一个出发、在另一个结束；如果没有奇点，从哪里出发都可以，而且最后会回到起点。画的时候别急着走进只剩一条路的死角，先把绕远的线画完。This is the mathematician's Euler path: count how many lines meet at each dot — dots with an odd count are odd points. If a figure has two odd points you must start at one and finish at the other; with none you can start anywhere and will end where you began. Avoid walking into a dead end early and clear the long loops first.
每一关都一定能画完吗？Can every level be completed?
能。每一关都是沿着一条连续的路线生成的，保证至少有一种一笔画完的走法。Yes. Each level is generated by drawing one continuous route, so at least one single-stroke solution always exists.
走错了怎么办？What if I go the wrong way?
点“撤销”退回一步，或点“重画”从头开始；提示会根据你现在的位置给出下一步。Undo steps back one line and Redraw starts over; the hint suggests the next dot from wherever you are.
「一笔画」免费吗？需要下载吗？Is One-Stroke Drawing free? Do I need to download anything?
完全免费，无需注册、下载或安装，打开网页就能玩，手机、平板和电脑都支持；游戏完全在你的浏览器本地运行，不会上传任何数据。It is completely free with no sign-up, download or install — just open the page on a phone, tablet or computer. The game runs entirely in your browser and nothing is uploaded.