fouryuan.cpp

在纯DOS下运行的TurboC3_ucos2_ucgui bug改进版本

/* opposite bo-lan expression writen on Nov.13.1999 */
#define N 30
#include <stdio.h>
#include <conio.h>
#include <string.h>
typedef struct unit{char symbol;int num1,num2,result;} node;
node Four[N]; /* four unit expression h*/
char inputs[N];  /* input stream ;i*/
char symbols[N]; /* char stream ;j*/
int process[N]; /*processcedur stream ;k*/
char B=' ';
int i=0,  // point to inputs[N]
     j=0, // point to symbols[N]
     k=0, //point to process[N]
     h=0;  // point to Four[N]

void init()
{printf("This is processgram of four unit expression\nPlease input an arithmetic \
expression\nexample: 2+4*(6-9/3+(5-12*4)/2+8)+12\n ");
 scanf("%s",inputs);
 strcat(inputs,"#");
 symbols[j]='~';
 j++;
}




void print()
{ int s;
  for(s=0;s<h;s++)
  printf("(%c,%d,%d,%d)\n",Four[s].symbol,Four[s].num1,Four[s].num2,Four[s].result);
}

 PUSH(char A[N],char a)
{
 A[j]=a;
 j++;
return 0;
}
 PUSH1( int A[N],char a)
{ a-=48; // change char to integer
 A[k]=a;
 k++;
 return 0;
}
 POP(char A[N])
{char d;
 d=A[j-1];
 j--;
return d;
}

Creat4Units()
{Four[h].symbol=symbols[j-1];
 Four[h].num1=process[k-2];
 Four[h].num2=process[k-1];
 if (Four[h].symbol=='+')
  Four[h].result=Four[h].num1+Four[h].num2;
 if (Four[h].symbol=='-')
  Four[h].result=Four[h].num1-Four[h].num2;
 if (Four[h].symbol=='*')
  Four[h].result=Four[h].num1*Four[h].num2;
 if (Four[h].symbol=='/')
  Four[h].result=Four[h].num1/Four[h].num2;
 k=k-2;
 j--;
 process[k]=Four[h].result;
 k++;
 h++;
 return 0;
}
 analyze()
{i=0;
 while(1)
  {if (inputs[i]>='0' && inputs[i]<='9')   // now only can input 0 to 9 ,can't 10 ,111
  {
    PUSH1(process,inputs[i]);
   i++;
  }
  else
      if (inputs[i]=='(')
	 {PUSH(symbols,'~');
	 i++;
	 }
	  else
	       if (inputs[i]=='+' || inputs[i]=='-' || inputs[i]=='*' || inputs[i]=='/')
		  {if (symbols[j-1]=='~')  //identifer  of rapen
		   {PUSH(symbols,inputs[i]);
		    i++;
		   }
		  else
		       if ((symbols[j-1]=='+'||symbols[j-1]=='-')&&(inputs[i]=='*'||inputs[i]=='/'))
			  {PUSH(symbols,inputs[i]);
			   i++;
			  }
			  else
			  {Creat4Units();
			  }
		  }
		  else
		    if (inputs[i]==')')
		    {if (symbols[j-1]=='~')
		     {B=POP(symbols);
		      i++;
		     }
		     else
		      {Creat4Units();
		      }
		    }
		    else
			if (inputs[i]=='#')
			{ if (symbols[j-1]=='~')
			  {break;
			   }
			  else
			  {Creat4Units();
			  }
			 }
			else{printf("The exptession is error!\n");
			     return(0);
			    }
		 }
   return(1); }


void main()
{
 init();
 analyze();
 print();
 getch();
}