#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX 1024
typedef int ElemType;
typedef struct _SqStack{
ElemType *base;
ElemType *top;
int stackSize;
}SqStack;
int InitStack(SqStack *S)
{
S->base = (ElemType *)malloc(MAX*sizeof(ElemType));
S->top = S->base;
S->stackSize = MAX;
return 1;
}
ElemType GetTop(SqStack *S)
{
return *(S->top - 1);
}
int Push(SqStack *S, ElemType e)
{
if(S->top - S->base >= S->stackSize){
return 0;
}
*(S->top++) = e;
}
int Pop(SqStack *S, ElemType *e)
{
if(S->top == S->base){
return 0;
}else{
*e = *(--S->top);
return 1;
}
}
int StackEmpty(SqStack *S)
{
if(S->top == S->base){
return 1;
}else{
return 0;
}
}
int ClearStack(SqStack *S)
{
S->top = S->base;
return 1;
}
int PrintStack(SqStack *S)
{
ElemType *p = S->base;
while(p != S->top){
printf("%c", (char)*p);
p++;
}
printf("\n");
return 1;
}
char OP[] = {7, '+', '-', '*', '/', '(', ')', '#'};
char PRE[][7] = {
{'>', '>', '<', '<', '<', '>', '>'},
{'>', '>', '<', '<', '<', '>', '>'},
{'>', '>', '>', '>', '<', '>', '>'},
{'>', '>', '>', '>', '<', '>', '>'},
{'<', '<', '<', '<', '<', '=', ' '},
{'>', '>', '>', '>', ' ', '>', '>'},
{'<', '<', '<', '<', '<', ' ', '='}
};
int In(char c, char *array)
{
int i;
for(i=1; i<=array[0]; i++){
if(c == array[i]){
return i;
}
}
return 0;
}
int Precede(char a, char b)
{
int na,nb;
na = In(a, OP) - 1;
nb = In(b, OP) - 1;
return PRE[na][nb];
}
int Operate(int a, char x, int b)
{
int ret;
switch(x){
case '+':
ret = a+b;
break;
case '-':
ret = a-b;
break;
case '*':
ret = a*b;
break;
case '/':
ret = a/b;
break;
}
return ret;
}
ElemType EvaluateExpression()
{
SqStack OPTR;
SqStack OPND;
int c;
int x;
int a;
int b;
InitStack(&OPTR);
InitStack(&OPND);
Push(&OPTR, '#');
c = getchar();
while(c != '#' || GetTop(&OPTR) != '#'){
if(!In(c, OP)){
Push(&OPND, c-'0');
c = getchar();
}else{
switch(Precede(GetTop(&OPTR), c) ){
case '<':
Push(&OPTR, c);
c = getchar();
break;
case '=':
Pop(&OPTR, (int *)&x);
c = getchar();
break;
case '>':
Pop(&OPTR, &x);
Pop(&OPND, &b);
Pop(&OPND, &a);
Push(&OPND, Operate(a, x, b));
break;
default:
return 0;
break;
}
}
}
return GetTop(&OPND);
}
void main()
{
printf("log.anycle.com\n\n");
printf("Conversion:\n");
printf("= %d\n", EvaluateExpression() );
printf("\n");
}