《C#高级编程》源代码的进.doc

/*程序名称:表达式计算器编译环境:Microsoft Visual C+ 6.0时间:200801*/*说明:采用树形结构处理表达式,按优先级运算结果,一个加,减,乘,除或数值为一个节点优先级如下:函数:4括号:3乘除:2加减:1*/#include #include #include #include #include using namespace std;const char NUM=0,1,2,3,4,5,6,7,8,9,.;const char OPERATION=+,-,*,/;const double PI=3.14159265358979;const double EE=2.71828182818281;class Fun /处理系统数学函数的类public:Fun(string o,int t,double l=0.0,double r=0.0):op(o),type(t),lvalue(l),rvalue(r)static string FUN;double calc();private:int type; /666 0 1 sin90 2 3! 3 3C2 string op; /函数类型double lvalue; /函数左边的值double rvalue; /函数右边的值static int FunNum;int Fun:FunNum=10;string Fun:FUN=!,sin,cos,tan,log,ln,C,A,-;/*函数说明:1:log是以10为底的工程对数2:ln 是以e为底的自然对数3:C 计算组合数 输入规则 如计算 3取2的组合 输入表达式 3C24:A 计算排列数 输入规则 如计算 3取2的排列 输入表达式 3A25:! 计算阶乘6: x的y次方 输入 xy*/int factorial(int n) /阶乘函数int i,s=1;for(i=1;iGetValue();rvalue=Right-GetValue();Expression=0;char op=GetOperation();switch(op)case +:return lvalue+rvalue;case -:return lvalue-rvalue;case *:return lvalue*rvalue;case /:return lvalue/rvalue;default:return 0;elsereturn value;bool Isnum(char c)for(int i=0;isizeof(NUM);i+)if(c=NUMi)return true;return false;bool Isoperation(char c)for(int i=0;isizeof(OPERATION);i+)if(c=OPERATIONi)return true;return false;Unit * Analyse(string exp) /分析表达式并生成链表int pri=0; /当前优先级int stat=1; /当前的读入状态 括号 0 运算符 1 其他 2Unit * head=NULL,* p=NULL;int i=0,explen;explen=exp.size();for(i=0;iNext=new Unit(pri+add_pri,c, ,0,0);p=p-Next;p-Pre=temp;else /其他的当做函数处理stat=2;string function=;while(iNext=new Unit(pri, ,function,0,2);p=p-Next;p-Pre=temp;return head;Unit * Calc(Unit * head) /计算双向链表基本单元的值Unit * p=head;while(p!=NULL)if(p-Type!=0) /非操作符string temp=p-Code;string op;double lvalue=0,rvalue=0;int l_point=0,r_point=0;int i=0,type=0;char ch;while(itemp.size() & (ch=temp.at(i),Isnum(ch)if(ch=.)l_point+;i+;continue;if(! l_point)lvalue*=10;lvalue+=(ch-0)*pow(10,-l_point);i+;if(l_point)l_point+;while(itemp.size() & (ch=temp.at(i),! Isnum(ch)op+=ch;type=1;i+;while(ivalue=f-calc();p=p-Next;return head;Node * Tree(Unit * head) /生成表达式树Node * root=NULL,* proot=NULL,* pbranch=NULL;Unit * p=head;int now_pri; /当前优先级bool hadop=false;while(p!=NULL)if(p-Type=0) /如果是一个操作符hadop=true;if(root=NULL)proot=new Node(p-Operation,p-PRI,1);root=proot;pbranch=root;now_pri=p-PRI;proot-Left=new Node( ,0,0,p-Pre-value);proot-Right=new Node( ,0,0,p-Next-value);elseif(p-PRIOperation,p-PRI,1); /新的树根proot-Left=root; /根的变换proot-Left-Head=proot;proot-Right=new Node( ,0,0,p-Next-value);proot-Right-Head=proot;root=proot;pbranch=proot; /右树枝的变换/pbranch-Right=new Node( ,0,0,p-Pre-value); /树枝右边取值else if(p-PRI=now_pri) /优先级相同,先算左边的Node * temp;temp=new Node(p-Operation,p-PRI,1);temp-Left=pbranch;if(pbranch-Head=NULL)proot=temp;root=proot;pbranch-Head=proot;elseNode * temp0;temp0=pbranch-Head;temp0-Right=temp;temp-Head=temp0;pbranch-Head=temp;pbranch=temp;pbranch-Right=new Node( ,0,0,p-Next-value);pbranch-Right-Head=pbranch;elseNode * temp;temp=new Node(p-Operation,p-PRI,1);pbranch-Right=temp;temp-Head=pbranch;pbranch=pbranch-Right;pbranch-Left=new Node( ,0,0,p-Pre-value);pbranch-Left-Head=pbranch;pbranch-Right=new Node( ,0,0,p-Next-value);pbranch-Right-Head=pbranch;now_pri=p-PRI;p=p-Next;if(! hadop)root=new Node( ,0,0,head-value);return root;int main()string exp;ifstream infile(test.txt,ios:in);while(! getline(infile,exp).eof()if(exp=)continue;Unit * h=Analyse(exp);h=Calc(h);Node * root=Tree(h);coutexp=GetValue()endl;return 0;备注:修正了上一篇的一个bug,支持负数运算.(3+2)*9)-(6/3)*sin90+1)/8+18*3=59.56.6+3.2*6=25.8sin60+3*2=6.866033+2*6/3+12/6=9sin30*2+3*6-sin90*(