subject_39655.htm

vc

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序号：39655 发表者：annehyf1024 发表日期：2003-05-12 17:57:47
<br>主题：请教一个菜鸟问题！
<br>内容：a(x,y)产生f(x)a(0.5*x,0.3*y)b(y),令x=0.5*x,y=0.3*y再继续替换，总共迭代3次，该怎样编程？<BR>我编了一个递归函数<BR>int count =0;<BR>string a(int x,int y)<BR>{<BR>&nbsp;&nbsp;string s;<BR>&nbsp;&nbsp;if(count=MAX_COUNT)//MAX_COUNY为最大迭代次数<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return "FA(x,y)B";<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;count++;<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;string s="x+"+a(x*0.5,y*0.5);<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return s;<BR>}<BR>总返回"FA(x,y)B"，结束条件应该怎样设呢？<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<BR> 
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回复者：qqwang 回复日期：2003-05-12 20:33:17
<br>内容：判断没问题，<BR>是你的string变量定义的有问题。。<BR>string是局部变量啦，<BR>每次修改都是修改的函数内部的string变量，<BR>把string设为static......
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回复者：annehyf1024 回复日期：2003-05-12 21:07:49
<br>内容：不对，我把s设为全局变量static string s，还是原样
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<font color=red>答案被接受</font><br>回复者：qqwang 回复日期：2003-05-13 12:00:04
<br>内容：<BR>//我仔细看了看，程序还有错误，修改如下:<BR>int count =0;<BR>string a(int x,int y)<BR>{<BR>&nbsp;&nbsp;static string s; //这里应该用静态变量<BR> //&nbsp;&nbsp; string s;<BR>&nbsp;&nbsp; if(count==MAX_COUNT)&nbsp;&nbsp;//判断相等用＝＝，而不是赋值运算符<BR>//&nbsp;&nbsp;if(count=MAX_COUNT)//MAX_COUNY为最大迭代次数<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return "FA(x,y)B";<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;count++;<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;s="x+"+a(x*0.5,y*.5);//这里string不能重复声明为局部变量<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;//string s="x+"+a(x*0.5,y*0.5);<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return s;<BR>}<BR>
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