【文件属性】：
文件名称：表达式运算优先级堆栈
文件大小：3KB
文件格式：TXT
更新时间：2013-12-03 17:32:01
堆栈表达式求值
#include"stdio.h"
char A[7]={'+','-','*','/','(',')','#'};
char B[7][7]={{'>','>','<','<','<','>','>'},
{'>','>','<','<','<','>','>'},
{'>','>','>','>','<','>','>'},
{'>','>','>','>','<','>','>'},
{'<','<','<','<','<','=','0'},
{'>','>','>','>','0','>','>'},
{'<','<','<','<','<','0','='}};
typedef struct stack1
{
int top;
int base;
char s[20];
}stack1;
typedef struct stack2
{
int top;
int base;
int s[20];
}stack2;
void Initstack1(stack1 *S)
{
S->top=S->base=0;
}
void Initstack2(stack2 *S)
{
S->top=S->base=0;
}
int push1(stack1 *S,char ch)
{
S->s[S->top]=ch;
S->top++;
}
int push2(stack2 *S,int ch)
{
S->s[S->top]=ch;
S->top++;
}
int search(char ch)
{
int i=0;
while(ch!=A[i])
{
i++;
}
return i;
}
char precede(char c1,char c2)
{
int i,j;
i=search(c1);
j=search(c2);
return B[i][j];
}
char gettop1(stack1 S)
{
char e;
if(S.top==S.base)
printf("!!!");
e=S.s[S.top-1];
return e;
}
int gettop2(stack2 S)
{
int e;
if(S.top==S.base)
printf("!!!");
e=S.s[S.top-1];
return e;
}
char pop1(stack1 *S)
{
if(S->top==S->base)
return('!');
else
{
S->top--;
return(S->s[S->top]);
}
}
int pop2(stack2 *S)
{
if(S->top==S->base)
return('!');
else
{
S->top--;
return(S->s[S->top]);
}
}
int operate(int a,char op,int b)
{
switch(op)
{
case '+':return(a+b);break;
case '-':return(a-b);break;
case '*':return(a*b);break;
case '/':return(a/b);break;
}
}
int main()
{
struct stack1 OPTR;
struct stack2 OPND;
char c,op;
int a,b,an;
Initstack1(&OPTR);
push1(&OPTR,'#');
Initstack2(&OPND);
c=getchar();
while(c!='#'||gettop1(OPTR)!='#')
{
if(c>='0'&&c<='9')
{
push2(&OPND,c-'0');
c=getchar();
do
{
if(c>='0'&&c<='9')
push2(&OPND,pop2(&OPND)*10+(c-'0'));
}while(c>='0'&&c<='9');
}
else
{
switch(precede(gettop1(OPTR),c))
{
case '<':
push1(&OPTR,c);c=getchar();break;
case '=':
c=pop1(&OPTR);c=getchar();break;
case '>':
op=pop1(&OPTR);a=pop2(&OPND);b=pop2(&OPND);
push2(&OPND,operate(b,op,a));break;
}//switch
} //else
} //while
an=pop2(&OPND);
printf("\nyour answer is:\n=%d",an);
}