公式构造

<p><!--[if gte mso 9]><xml><w:WordDocument><w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel><w:DisplayHorizontalDrawingGridEvery>0</w:DisplayHorizontalDrawingGridEvery><w:DisplayVerticalDrawingGridEvery>2</w:DisplayVerticalDrawingGridEvery><w:DocumentKind>DocumentNotSpecified</w:DocumentKind><w:DrawingGridVerticalSpacing>7.8</w:DrawingGridVerticalSpacing><w:View>Normal</w:View><w:Compatibility></w:Compatibility><w:Zoom>0</w:Zoom></w:WordDocument></xml><![endif]--><span style="font-size: 10.5pt; font-family: '宋体';">&nbsp;&nbsp;&nbsp; 给两items数<font face="Times New Roman">x,y</font><font face="宋体">，构造公式</font><font face="Times New Roman">a&nbsp;op1&nbsp;b&nbsp;op2&nbsp;c&nbsp;op3&nbsp;d</font><font face="宋体">。</font></span><span style="font-size: 10.5pt; font-family: '宋体';">其中<font face="Times New Roman">a,b,c,d</font><font face="宋体">四items数中，两items数为</font><font face="Times New Roman">x</font><font face="宋体">，两items数为</font><font face="Times New Roman">y</font><font face="宋体">，</font><font face="Times New Roman">op1,op2,op3</font><font face="宋体">可以为</font><font face="Times New Roman">+</font><font face="宋体">，</font><font face="Times New Roman">-</font><font face="宋体">，</font><font face="Times New Roman">*</font><font face="宋体">。</font></span><span style="font-size: 10.5pt; font-family: '宋体';">该公式运算方法如下，从左到右计算，无视运算符优先级。</span><span style="font-size: 10.5pt; font-family: '宋体';">给<font face="Times New Roman">x</font><font face="宋体">，</font><font face="Times New Roman">y</font><font face="宋体">和答案，问有多少种构造公式的方法？</font></span></p> <p><span style="font-size: 10.5pt; font-family: '宋体';">注：公式中<font face="Times New Roman">7</font><font face="宋体">items元素（</font><font face="Times New Roman">a,b,c,d,op1,op2,op3</font><font face="宋体">）有一items元素不一样则表示两items公式不一样。</font></span></p>

<p><!--[if gte mso 9]><xml><w:WordDocument><w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel><w:DisplayHorizontalDrawingGridEvery>0</w:DisplayHorizontalDrawingGridEvery><w:DisplayVerticalDrawingGridEvery>2</w:DisplayVerticalDrawingGridEvery><w:DocumentKind>DocumentNotSpecified</w:DocumentKind><w:DrawingGridVerticalSpacing>7.8</w:DrawingGridVerticalSpacing><w:View>Normal</w:View><w:Compatibility></w:Compatibility><w:Zoom>0</w:Zoom></w:WordDocument></xml><![endif]--><span style="font-size: 10.5pt; font-family: '宋体';">一行输入三items数字：<font face="Times New Roman">x</font><font face="宋体">，</font><font face="Times New Roman">y</font><font face="宋体">，</font><font face="Times New Roman">ans</font><font face="宋体">，</font><font face="Times New Roman">ans</font><font face="宋体">为答案。</font></span><span style="font-size: 10.5pt; font-family: '宋体';">其中<font face="Times New Roman">-100&lt;=x</font><font face="宋体">，</font><font face="Times New Roman">y&lt;=100</font><font face="宋体">，</font><font face="Times New Roman">-</font></span><span style="font-size: 10.5pt; font-family: 'Times New Roman';">100000000</span><span style="font-size: 10.5pt; font-family: '宋体';">&lt;=ans&lt;=</span><span style="font-size: 10.5pt; font-family: 'Times New Roman';">100000000</span><span style="font-size: 10.5pt; font-family: '宋体';">.</span></p>

<p><!--[if gte mso 9]><xml><w:WordDocument><w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel><w:DisplayHorizontalDrawingGridEvery>0</w:DisplayHorizontalDrawingGridEvery><w:DisplayVerticalDrawingGridEvery>2</w:DisplayVerticalDrawingGridEvery><w:DocumentKind>DocumentNotSpecified</w:DocumentKind><w:DrawingGridVerticalSpacing>7.8</w:DrawingGridVerticalSpacing><w:View>Normal</w:View><w:Compatibility></w:Compatibility><w:Zoom>0</w:Zoom></w:WordDocument></xml><![endif]--><span style="font-size: 10.5pt; font-family: '宋体';">每items测试数据输出一items数，表示构造公式的方法数。</span></p>