My first

markdown测试

priority_queue<int> ins, del;
void insert(int x) {ins.push(x);}
void deletee(int x) {del.push(x);}
int top() {
    while (!del.empty() and !ins.empty() and del.top() == ins.top()) {del.pop(); ins.pop();}
    return ins.top();
}

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$LaTeX$测试

$$\sqrt{1+\sqrt[^p\!]{1+a^2}}$$ $$\int_a^b f(x)\mathrm{d}x$$ $$\left(\sum_{k=\frac{1}{2}}^{N^2}\frac{1}{k}\right)$$ $$\mathbf{X} = \left( \begin{array}{ccc} x_{11} & x_{12} & \ldots \\ x_{21} & x_{22} & \ldots \\ \vdots & \vdots & \ddots \end{array} \right)$$ $$y = \left\{ \begin{array}{ll} a & \textrm{if $d>c$}\\ b+x & \textrm{in the morning}\\ l & \textrm{all day long} \end{array} \right.$$