Markdown测试

一级标题

二级标题

三级标题

四级标题

这是一个 示例链接.

引用块测试

• Red
  • 列表测试
    • 列表测试

分割线

---

斜体

粗体

代码块 printf()

/*代码测试*/
#include<cstdio>
#define N 20010

void dfs(int x){
  int i;
  for(i=G[x];i;i=NXT[i])ans[V[i]]=root(Q[i])==root(W[i]);
  for(i=g[x];i;i=nxt[i])if(root(q[i])!=root(w[i]))link(q[i],w[i]),dfs(v[i]),cut(q[i],w[i]);else dfs(v[i]);
}
int main(){
  for(scanf("%d%d",&n,&m),i=1;i<=m;ans[i++]=-1){
    scanf("%d",&op);
    if(op==1)scanf("%d%d",&x,&y),add(last,id[i]=i,x,y),last=i;
    if(op==2)scanf("%d",&x),last=id[i]=id[x];
    if(op==3)scanf("%d%d",&x,&y),ADD(last,i,x,y),id[i]=last;
  }
  for(dfs(0),i=1;i<=m;i++)if(~ans[i])printf("%d\n",ans[i]);
  return 0;
}

行内公式： \(a+b​\)

行间公式：$$f(x) =
\begin{cases}
x^2 \qquad & a \gt 0 \
e^x \qquad & a \le 0
\end{cases}$$

\[\mathbf{V}_1 \times \mathbf{V}_2 = \begin{vmatrix} \mathbf{i} & \mathbf{j} & \mathbf{k} \\ \frac{\partial X}{\partial u} & \frac{\partial Y}{\partial u} & 0 \\ \frac{\partial X}{\partial v} & \frac{\partial Y}{\partial v} & 0 \\ \end{vmatrix} \]

\[\left( \begin{array}{ccc} a & b & c \\ d & e & f \\ g & h & i \end{array} \right) \]