graphviz入门

digraph d {
	edge[color=red, arrowhead=vee, fontcolor=gray];
	node[style=filled, color=gray, fontcolor=dodgerblue2, shape=box]

	a[shape=box, label=" 电灯不工作了"];
	b[label=" 电源\n接好了吗？", shape=diamond];
	d[label=" 灯泡\n烧毁了吗？", shape=diamond];
	e[label=" 更换灯泡", rank=same];
	
	c[label=" 接好电源"];
	f[label=" 修理电灯"];

	// b,c; d f;水平排列
	{ rank=same b c}
	{ rank=same d f}

	a -> b;
	b -> d[label=" 是"];
	d -> e[label=" 是"];

	b -> c[label=" 否"];
	d -> f[label=" 否"];
}