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user: user-1
content: 仅供参考：/*--------------------------------------- 函数型计算器(VC++6.0,Win32 Console) 功能： 目前提供了10多个常用数学函数:     ⑴正弦sin     ⑵余弦cos     ⑶正切tan     ⑷开平方sqrt     ⑸反正弦arcsin     ⑹反余弦arccos     ⑺反正切arctan     ⑻常用对数lg     ⑼自然对数ln     ⑽ｅ指数exp     ⑾乘幂函数^     ⑿向上取整ceil     ⒀向下取整floor     ⒁四舍五入取整round 用法： 如果要求2的32次幂，可以打入2^32<回车> 如果要求30度角的正切可键入tan(Pi/6)<回车> 注意不能打入：tan(30)<Enter> 如果要求1.23弧度的正弦，有几种方法都有效： sin(1.23)<Enter> sin 1.23 <Enter> sin1.23  <Enter> 如果验证正余弦的平方和公式,可打入sin(1.23)^2+cos(1.23)^2 <Enter>或sin1.23^2+cos1.23^2 <Enter> 此外两函数表达式连在一起,自动理解为相乘如：sin1.23cos0.77+cos1.23sin0.77就等价于sin(1.23)*cos(0.77)+cos(1.23)*sin(0.77) 当然你还可以依据三角变换，再用sin(1.23+0.77)也即sin2验证一下。 本计算器充分考虑了运算符的优先级因此诸如：2+3*4^2 实际上相当于：2+(3*(4*4)) 另外函数名前面如果是数字,那么自动认为二者相乘. 同理，如果某数的右侧是左括号，则自动认为该数与括弧项之间隐含一乘号。 如：3sin1.2^2+5cos2.1^2 相当于3*sin2(1.2)+5*cos2(2.1) 又如：4(3-2(sqrt5-1)+ln2)+lg5 相当于4*(3-2*(√5 -1)+loge(2))+log10(5) 此外，本计算器提供了圆周率 Pi键入字母时不区分大小写,以方便使用。 ----------------------------------------*/ #include <iostream> #include <iomanip> #include <cstdlib> #include <cstring> #include <cctype> #include <cmath> #include <stdio.h> #include <string.h> #include <windows.h> using namespace std; const char Tab=0x9; const int  DIGIT=1; const int MAXLEN=16384; char s[MAXLEN],*endss; int pcs=15; double round(double dVal, short iPlaces) {//iPlaces>=0     char s[30];     double dRetval;      sprintf(s,"%.*lf",iPlaces,dVal);     sscanf(s,"%lf",&dRetval);     return (dRetval); } double fun(double x,char op[],int *iop) {     while (op[*iop-1]<32) //本行使得函数嵌套调用时不必加括号,如 arc sin(sin(1.234)) 只需键入arc sin sin 1.234<Enter>         switch (op[*iop-1]) {         case  7: x=sin(x);    (*iop)--;break;         case  8: x=cos(x);    (*iop)--;break;         case  9: x=tan(x);    (*iop)--;break;         case 10: x=sqrt(x);   (*iop)--;break;         case 11: x=asin(x);   (*iop)--;break;         case 12: x=acos(x);   (*iop)--;break;         case 13: x=atan(x);   (*iop)--;break;         case 14: x=log10(x);  (*iop)--;break;         case 15: x=log(x);    (*iop)--;break;         case 16: x=exp(x);    (*iop)--;break;         case 17: x=ceil(x);   (*iop)--;break;         case 18: x=floor(x);  (*iop)--;break;         case 19: x=round(x,0);(*iop)--;break;         }     return x; } double calc(char *expr,char **addr) {     static int deep; //递归深度     static char *fname[]={"sin","cos","tan","sqrt","arcsin","arccos","arctan","lg","ln","exp","ceil","floor","round",NULL};     double ST[10]={0.0}; //数字栈     char op[10]={'+'}; //运算符栈     char c,*rexp,*pp,*pf;     int ist=1,iop=1,last,i;      if (!deep) {         pp=pf=expr;         do {             c = *pp++;             if (c!=' '&& c!=Tab)                 *pf++ = c;         } while (c!='\0');     }     pp=expr;     if ((c=*pp)=='-'||c=='+') {         op[0] = c;         pp++;     }     last = !DIGIT;     while ((c=*pp)!='\0') {         if (c=='(') {//左圆括弧             deep++;             ST[ist++]=calc(++pp,addr);             deep--;             ST[ist-1]=fun(ST[ist-1],op,&iop);             pp = *addr;             last = DIGIT;             if (*pp == '('||isalpha(*pp) && strnicmp(pp,"Pi",2)) {//目的是：当右圆括弧的右恻为左圆括弧或函数名字时，默认其为乘法                 op[iop++]='*';                 last = !DIGIT;                 c = op[--iop];                 goto operate ;             }         }         else if (c==')') {//右圆括弧             pp++;             break;         } else if (isalpha(c)) {             if (!strnicmp(pp,"Pi",2)) {                 if (last==DIGIT) {                     cout<< "π左侧遇）" <<endl;exit(1);                 }                 ST[ist++]=3.14159265358979323846264338328;                 ST[ist-1]=fun(ST[ist-1],op,&iop);                 pp += 2;                 last = DIGIT;                 if (!strnicmp(pp,"Pi",2)) {                     cout<< "两个π相连" <<endl;exit(2);                 }                 if (*pp=='(') {                     cout<< "π右侧遇（" <<endl;exit(3);                 }             } else {                 for (i=0; (pf=fname[i])!=NULL; i++)                     if (!strnicmp(pp,pf,strlen(pf))) break;                 if (pf!=NULL) {                     op[iop++] = 07+i;                     pp += strlen(pf);                 } else {                     cout<< "陌生函数名" <<endl;exit(4);                 }             }         } else if (c=='+'||c=='-'||c=='*'||c=='/'||c=='%'||c=='^') {             char cc;             if (last != DIGIT) {                 cout<< "运算符粘连" <<endl;exit(5);             }             pp++;             if (c=='+'||c=='-') {                 do {                     cc = op[--iop];                     --ist;                     switch (cc) {                     case '+':  ST[ist-1] += ST[ist];break;                     case '-':  ST[ist-1] -= ST[ist];break;                     case '*':  ST[ist-1] *= ST[ist];break;                     case '/':  ST[ist-1] /= ST[ist];break;                     case '%':  ST[ist-1] = fmod(ST[ist-1],ST[ist]);break;                     case '^':  ST[ist-1] = pow(ST[ist-1],ST[ist]);break;                     }                 } while (iop);                 op[iop++] = c;             } else if (c=='*'||c=='/'||c=='%') { operate:        cc = op[iop-1];                 if (cc=='+'||cc=='-') {                     op[iop++] = c;                 } else {                     --ist;                     op[iop-1] = c;                     switch (cc) {                     case '*':  ST[ist-1] *= ST[ist];break;                     case '/':  ST[ist-1] /= ST[ist];break;                     case '%':  ST[ist-1] = fmod(ST[ist-1],ST[ist]);break;                     case '^':  ST[ist-1] = pow(ST[ist-1],ST[ist]);break;                     }                 }             } else {                 cc = op[iop-1];                 if (cc=='^') {                     cout<< "乘幂符连用" <<endl;exit(6);                 }                 op[iop++] = c;             }             last = !DIGIT;         } else {             if (last == DIGIT) {                 cout<< "两数字粘连" <<endl;exit(7);             }             ST[ist++]=strtod(pp,&rexp);             ST[ist-1]=fun(ST[ist-1],op,&iop);             if (pp == rexp) {                 cout<< "非法字符" <<endl;exit(8);             }             pp = rexp;             last = DIGIT;             if (*pp == '('||isalpha(*pp)) {                 op[iop++]='*';                 last = !DIGIT;                 c = op[--iop];                 goto operate ;             }         }     }     *addr=pp;     if (iop>=ist) {         cout<< "表达式有误" <<endl;exit(9);     }     while (iop) {         --ist;         switch (op[--iop]) {         case '+':  ST[ist-1] += ST[ist];break;         case '-':  ST[ist-1] -= ST[ist];break;         case '*':  ST[ist-1] *= ST[ist];break;         case '/':  ST[ist-1] /= ST[ist];break;         case '%':  ST[ist-1] = fmod(ST[ist-1],ST[ist]);break;         case '^':  ST[ist-1] = pow(ST[ist-1],ST[ist]);break;         }     }     return ST[0]; } int main(int argc,char **argv) {     int a;      if (argc<2) {         if (GetConsoleOutputCP()!=936) system("chcp 936>NUL");//中文代码页         cout << "计算函数表达式的值。"<<endl<<"支持(),+,-,*,/,%,^,Pi,sin,cos,tan,sqrt,arcsin,arccos,arctan,lg,ln,exp,ceil,floor,round"<<endl;         while (1) {             cout << "请输入表达式：";             gets(s);             if (s[0]==0) break;//             cout << s <<"=";             cout << setprecision(15) << calc(s,&endss) << endl;         }     } else if (argc==2 && 0==strcmp(argv[1],"/?")) {         if (GetConsoleOutputCP()!=936) system("chcp 936>NUL");//中文代码页         cout << "计算由≥1个命令行参数给出的函数表达式的值。最后一个参数是.0～.15表示将计算结果保留小数0～15位"<<endl<<"支持(),+,-,*,/,%,^^,Pi,sin,cos,tan,sqrt,arcsin,arccos,arctan,lg,ln,exp,ceil,floor,round"<<endl;     } else {         strncpy(s,argv[1],MAXLEN-1);s[MAXLEN-1]=0;         if (argc>2) {             for (a=2;a<argc-1;a++) strncat(s,argv[a],MAXLEN-1);//将空格间隔的各参数连接到s             if (1==sscanf(argv[a],".%d",&pcs) && 0<=pcs && pcs<=15) {//最后一个参数是.0～.15表示将计算结果保留小数0～15位                 printf("%.*lf\n",pcs,calc(s,&endss));             } else {                 strncat(s,argv[a],MAXLEN-1);                 printf("%.15lg\n",calc(s,&endss));             }         } else {             printf("%.15lg\n",calc(s,&endss));         }     }     return 0; }

user: user-2
content: 遇到数字：直接输出   遇到'('：压栈   遇到')'：持续出栈，如果出栈的符号不是'('则输出，否则终止出栈。   遇到符号则判断该符号与栈顶符号的运算优先级，如果栈顶符号的运算优先级高，则出栈并输出，直到优先级相等或栈为空；如果栈顶符号的运算优先级低于或等于当前符号的运算优先级，则将当前符号压栈。   处理完字符串后将栈中剩余的符号全部输出。   以下代码把把每一步的栈的情况都会打印，楼主不想显示的话直接注释掉cout以及调用show的地方就好  #include <cstdlib> #include <iostream> #include <stdlib.h> #include<iomanip> using namespace std; class node { public: 	char oper; 	double value; 	node *next; 	node(char c,double v,node *nextval) 	{ 		oper=c; 		value=v; 		next=nextval; 	} 	~node(){}; }; class stack {   public: 	node *top; 	stack() 	{ 		node *head=new node(' ',0,NULL); 		top=head; 	} 	~stack() 	{ 		node *tem; 		while(top->next!=NULL) 		{ 			tem=top; 			top=top->next; 			delete tem;                       		} 	} 	void show()        	{ 		node *temp; 		temp=top; 		if(temp->next==NULL) 		{ 			cout<<"栈空!"; 		} 		else 		{ 			cout<<"栈中元素:"; 			for(;temp->next!=NULL;temp=temp->next) 			{ 				if(temp->oper=='#') 					cout<<temp->value<<" "; 				else 					cout<<temp->oper<<" "; 			} 		} 		cout<<endl; 	} 	void push(char c,double v) 	{ 		node *tem=new node(c,v,top); 		top=tem;      	} 	node* pop() 	{ 		node *tem; 		tem=top; 		top=top->next; 		return tem; 	}        }; int main(int argc, char *argv[]) { 	stack mystack; 	node *tem,*tem2; 	int i,j=0,len,count=0; 	char s1[50],s2[50]; 	cout<<"输入中缀表达式(四则运算,包含括号):"; 	gets(s2); 	len=strlen(s2); 	for(i=0;i<len;i++) 	{ 		if(s2[i]=='(') 		{ 			mystack.push('(',0); 			mystack.show(); 		} 		else if(s2[i]>='0'&&s2[i]<='9') 		{ 			s1[count]=s2[i]; 			count++;                      		} 		else if(s2[i]=='*'||s2[i]=='/') 		{ 			s1[count]=' '; 			count++; 			if(mystack.top->oper=='*'||mystack.top->oper=='/') 			{ 				tem=mystack.pop(); 				s1[count]=tem->oper; 				count++; 				delete tem;  				mystack.show(); 			} 			mystack.push(s2[i],0); 			mystack.show(); 		} 		else if(s2[i]=='+'||s2[i]=='-') 		{ 			s1[count]=' '; 			count++; 			if(mystack.top->oper=='*'||mystack.top->oper=='/'||mystack.top->oper=='-'||mystack.top->oper=='+') 			{ 				tem=mystack.pop(); 				s1[count]=tem->oper; 				count++; 				delete tem;    				mystack.show(); 			} 			mystack.push(s2[i],0);    			mystack.show(); 		} 		else if(s2[i]==')') 		{ 			while(mystack.top->oper!='(') 			{ 				tem=mystack.pop(); 				s1[count]=tem->oper; 				count++; 				delete tem;   				mystack.show(); 			} 			tem=mystack.pop(); 			delete tem; 			mystack.show(); 		}         	} 	while(mystack.top->next!=NULL) 	{ 		tem=mystack.pop(); 		s1[count]=tem->oper; 		count++; 		delete tem;     		mystack.show(); 	} 	s1[count]='\0'; 	cout<<"后缀表达式为:"<<s1<<endl; 	bool change1,change2; 	change1=change2=false; 	for(i=0;i<count;i++) 	{ 		int x;        		char s[20]; 		if(s1[i]>='0'&&s1[i]<='9') 		{ 			s[j]=s1[i]; 			j++; 			change1=true;         		} 		else if(s1[i]!='\0') 		{ 			if(change1) 			{ 				change2=true; 				change1=false; 				s[j]='\0'; 				j=0; 			} 		} 		if(change2) 		{ 			x=atoi(s); 			s[j]='\0'; 			change2=false; 			mystack.push('#',x);    			mystack.show(); 		}  		if(s1[i]=='+'||s1[i]=='-'||s1[i]=='*'||s1[i]=='/') 		{ 			double sum=0; 			if(s1[i]=='+') 			{ 				tem=mystack.pop(); 				mystack.show(); 				tem2=mystack.pop(); 				mystack.show(); 				sum=tem2->value+tem->value; 				cout<<tem2->value<<"+"<<tem->value<<"="<<sum<<endl; 			} 			else if(s1[i]=='-') 			{ 				tem=mystack.pop(); 				mystack.show(); 				tem2=mystack.pop(); 				mystack.show(); 				sum=tem2->value-tem->value; 				cout<<tem2->value<<"-"<<tem->value<<"="<<sum<<endl; 			} 			else if(s1[i]=='*') 			{ 				tem=mystack.pop(); 				mystack.show(); 				tem2=mystack.pop(); 				mystack.show(); 				sum=tem2->value*tem->value;   				cout<<tem2->value<<"*"<<tem->value<<"="<<sum<<endl; 			} 			else if(s1[i]=='/') 			{ 				tem=mystack.pop(); 				mystack.show(); 				tem2=mystack.pop(); 				mystack.show(); 				sum=tem2->value/tem->value; 				cout<<tem2->value<<"/"<<tem->value<<"="<<fixed<<setprecision(2)<<sum<<endl; 			} 			delete tem;	   			delete tem2; 			mystack.push('#',sum);    			mystack.show(); 		} 	} 	tem=mystack.pop(); 	mystack.show(); 	cout<<"结果为:"<<fixed<<setprecision(2)<<tem->value<<endl; 	delete tem; 	system("PAUSE"); 	return EXIT_SUCCESS; }