```mermaid   #输入，进入书写语言       #暂不考虑特殊字符
graph LR   #  TB/TD - 从上到下,BT - 从下到上,RL - 从右到左,LR - 从左到右
1 --> 2    #效果看下图

节点形状

```mermaid
graph LR
start1("圆边矩形") -->start2[矩形]-->start3((圆))-->start4>非对称]-->start5{菱形}

节点连接

graph LR
 A --> B --- C-.-D-.->E-.虚线.-F--实线-->G--箭头-->H==粗线==>I

子图

```mermaid
graph TB
    c1-->a2
    subgraph one
    a1-->a2
    end
    subgraph two
    b1-->b2
    end
    subgraph three
    c1-->c2
    end

graph LR
    c1-->a2
    subgraph one
    a1-->a2
    end
    subgraph two
    b1-->b2
    end
    subgraph three
    c1-->c2
    end