c语言实现中缀,后缀,前缀表达式转换并求值

c语言实现中缀,后缀,前缀表达式转

换并求值

c语言实现中缀,后缀,前缀表达式转换并求值九#include #include #define MAXNUM 100 typedef struct Node//定义存储中缀表达式的结点类型{int data; int data1; char data2; struct Node *next; }Lnode; typedef struct Node2//定义存储前缀表达式的结点类型{int data; int data1; char data2; struct Node2 *next; struct Node2 *prior; }Lnode2; typedef int selemtype1;//定义运算数栈的结点typedef struct//定义运算数栈的类型{selemtype1 *base; selemtype1 *top; }sqstack1; void InitStack1(sqstack1 &s)//新建一个空运算数栈{=(selemtype1 *)malloc(MAXNUM*sizeof(selemtype1));

=; if(!) printf(“出错：申请空间失败！\\n”); } void Push1(sqstack1 &s,selemtype1 &e)//运算数栈，入栈：插入元素e为新的栈顶元素{ if(>=MAXNUM) printf(“出错：表达式过长！1\\n”); *++ =e; } void GetTop1(sqstack1 s,selemtype1 &e)//运算数栈，用e返回栈顶元素{e=*(); } void Popopnd1(sqstack1 &s,selemtype1 &e) //运算数栈，退栈：删除栈顶元素，并用e返回其值{e=*--; } int stackempy1(sqstack1 s) //运算数栈，若为空栈返回1，否则返回0 {if(==) return 1; else return 0; } typedef char selemtype2;//定义运算符栈的结点类型typedef struct//定义运算符栈类型{selemtype2 *base; selemtype2 *top; }sqstack2; void InitStack2(sqstack2 &s)//新建一个空运算符栈{=(selemtype2 *)malloc(MAXNUM*sizeof(selemtype2)); =; if(!) printf(“出错：申请空间失败！

\\n”); } void Push2(sqstack2 &s,selemtype2 &e)//运算符栈，入栈：插入元素e为新的栈顶元素{ if(>=MAXNUM) printf(“出错：表达式过长！2\\n”); *++ =e; } void GetTop2(sqstack2 s,selemtype2 &e)//运算符栈，用e返回栈顶元素{e=*(); } void Popopnd2(sqstack2 &s,selemtype2 &e) //运算符栈，退栈：删除栈顶元素，并用e返回其值{e=*--; } int stackempy2(sqstack2 s) //运算符栈，若为空栈返回1，否则返回0 {if(==) return 1; else return 0; } void priority(char c,int &i)//确定运算符优先级{if (c==‘*’||c==‘/’||c==‘%’) i=2 ; else if (c==‘+’||c==‘-’) i=1 ; else i=0; } int compare(char a,char b)//比较栈顶元素运算符与外部运算符优先级大小，外部优先级大则返回1，反之返回0 {int in,out; priority(a,in); priority(b,out); if(out>in) return 1; else return 0; } void Operat(sqstack1 &OPND,sqstack2

&OPTR) {int num1,num2,num; char c; Popopnd1(OPND,num2);

Popopnd1(OPND,num1);

Popopnd2(OPTR,c); switch(c) {case ‘+’:num=num1+num2;break; case ‘-’:num=num1-num2;break; case ‘*’:num=num1*num2;break; case ‘/’:num=num1/num2;break; case ‘%’:num=num1%num2;break; } Push1(OPND,num); } void Operatqianzhui(sqstack1 &OPND,sqstack2 &OPTR) {int num1,num2,num; char c; Popopnd1(OPND,num1);

Popopnd1(OPND,num2);

Popopnd2(OPTR,c); switch(c) {case ‘+’:num=num1+num2;break; case ‘-’:num=num1-num2;break; case ‘*’:num=num1*num2;break; case ‘/’:num=num1/num2;break; case ‘%’:num=num1%num2;break; } Push1(OPND,num); }void

houzhuiqiuzhi(Lnode *p,int &e) {sqstack1 OPND; //运算数栈sqstack2 OPTR; //运算符栈int n; char c; p=p->next; InitStack1(OPND); InitStack2(OPTR); while(p) {switch(p->data) {case 1:n=p->data1; Push1(OPND,n); break; case 2:c=p->data2; Push2(OPTR,c); Operat(OPND,OPTR); break; default:printf(“结点有误”); brea k; } p=p->next; } Popopnd1(OPND,n); e=n; } void zhongzhui(Lnode *p) {sqstack1 OPND; //运算数栈sqstack2 OPTR; //运算符栈int n; //后缀表达式求值//中缀表达式求值char c,c2; Lnode *first; first=p; p=p->next; InitStack1(OPND); InitStack2(OPTR); while(!stackempy2(OPTR)||p) {while(p) {switch(p->data) {case 1:n=p->data1; Push1(OPND,n); break; case 2:c=p->data2; if(stackempy2(OPTR)) Push2(OPTR,c); else { switch(c)