C++ SLR 加减乘除 小数运算

E->E+E

E->E-E

E->E*E

E->E/E

E->(E)

E->digit                                    //也可以换成id     适当的改动

#include<iostream>
#include<stdio.h>
#include<stack>
#include<string.h>
using namespace std;
int flag=0;
stack<int> S;                                                          //状态栈
float T[100];                                                               //属性栈
int top=0;                                                               //属性栈栈顶
float sum=0;                                                             //digit的真实值
double SUM=0;
double temp=0.1;
char s[100];                                                              //输入
int sptr=0;
int p1;
char ch;
int action1[14][8]={{1,0,0,0,0,1,0,0},                            //action表的移进规约错误部分信息,1表示移进，2表示规约，0表示错误，3表示接受
                 {0,1,1,1,1,0,0,3},
                 {1,0,0,0,0,1,0,0},
                 {0,2,2,2,2,0,2,2},
                 {1,0,0,0,0,1,0,0},
                 {1,0,0,0,0,1,0,0},
                 {1,0,0,0,0,1,0,0},
                 {1,0,0,0,0,1,0,0},
                 {0,1,1,1,1,0,1,0},
                 {0,2,2,1,1,0,2,2},
                 {0,2,2,1,1,0,2,2},
                 {0,2,2,2,2,0,2,2},
                  {0,2,2,2,2,0,2,2},
                 {0,2,2,2,2,0,2,2},};
int action2[14][8]={{3,0,0,0,0,2,0,0},                            //action表的数字部分信息,数字表示状态，或者产生式号
                 {0,4,5,6,7,0,0,-1},
                 {3,0,0,0,0,2,0,0},
                 {0,6,6,6,6,0,6,6},
                 {3,0,0,0,0,2,0,0},
                 {3,0,0,0,0,2,0,0},
                 {3,0,0,0,0,2,0,0},
                 {3,0,0,0,0,2,0,0},
                 {0,4,5,6,7,0,13,0},
                 {0,1,1,6,7,0,1,1},
                 {0,2,2,6,7,0,2,2},
                 {0,3,3,3,3,0,3,3},
                 {0,4,4,4,4,0,4,4},
                 {0,5,5,5,5,0,5,5},};
int Goto[14]={1,-1,8,-1,9,10,11,12,-1,-1,-1,-1,-1,-1};               //goto表
int chan[6]={3,3,3,3,3,1};
int zhong(char t)
{
 if(t=='d')return 0;
 else if(t=='+')return 1;
 else if(t=='-')return 2;
 else if(t=='*')return 3;
 else if(t=='/')return 4;
 else if(t=='(')return 5;
 else if(t==')')return 6;
 else if(t=='$')return 7;
}
void fenxi(int m,char n)
{
 if(action1[m][zhong(n)]==1)                              //移进
 {
  //printf("%d\t移进!",S.top());
  if(ch=='d')
   {/*cout<<T[top]<<endl;*/}
  else
  {/*cout<<ch<<endl;*/top++;}
  S.push(action2[m][zhong(n)]);
  sptr++;
  ch=s[sptr];
 }
 else if(action1[m][zhong(n)]==2)                        //规约
 {
  //printf("%d\t规约!",S.top());
  if(action2[m][zhong(n)]==1)
  {T[top-2]=T[top-2]+T[top];/*cout<<"E->E+E"<<endl*/;top=top-2;}
  else if(action2[m][zhong(n)]==2)
  {T[top-2]=T[top-2]-T[top];/*cout<<"E->E-E"<<endl*/;top=top-2;}
  else if(action2[m][zhong(n)]==3)
  {T[top-2]=T[top-2]*T[top];/*cout<<"E->E*E"<<endl*/;top=top-2;}
  else if(action2[m][zhong(n)]==4)
  {
   if(T[top]!=0)
   {
    T[top-2]=T[top-2]/T[top];
          //cout<<"E->E/E"<<endl;
          top=top-2;
   }
   else
   {
    flag=2;
    printf("\nerror!除号不能为零！\n");
   }
  }
  else if(action2[m][zhong(n)]==5)
  {T[top-2]=T[top-1];/*cout<<"E->(E)"<<endl;*/top=top-2;}
  else if(action2[m][zhong(n)]==6)
  {/*cout<<"E->digit"<<endl;*/}
  for(p1=0;p1<chan[action2[m][zhong(n)]-1];p1++)
   S.pop();
  S.push(Goto[S.top()]);
 }
 else if(action1[m][zhong(n)]==0)                           //错误
 {
  flag=2;
  cout<<"error!"<<endl;
 }
 else if(action1[m][zhong(n)]==3)                         //接受
  flag=1;
}
void FENXI()
{
 int length;
 ch=s[sptr];
 //printf("栈顶\t动作\n");
 while(1)
 {
  if(s[sptr]>='0'&&s[sptr]<='9')
  {
   while(s[sptr]>='0'&&s[sptr]<='9')
   {
    sum=sum*10+s[sptr]-48;
    sptr++;
   }
   if(s[sptr]=='.')
   {
    sptr++;
    while(s[sptr]>='0'&&s[sptr]<='9')
    {
     SUM=SUM+(s[sptr]-48)*temp;
     sptr++;
     temp=temp*0.1;
    }
   }
   top++;
   sptr--;
   T[top]=sum+SUM;
   sum=0;
   SUM=0;
   ch='d';
  }
  fenxi(S.top(),ch);
  if(flag==1)
  {
   cout<<"表达式正确！"<<endl;
   length=strlen(s);
   s[length-1]=s[length];
   cout<<s<<"="<<T[top]<<endl;
   break;
  }
  if(flag==2)
  {
   cout<<"重新输入！"<<endl;
   break;
  }
 }
}
int main()
{
 while(flag==0||flag==2)
 {
  for(p1=0;p1<S.size();p1++)
   S.pop();
  for(p1=0;p1<100;p1++)
  {s[p1]=0;T[p1]=0;}
  top=sptr=sum=flag=0;
  temp=0.1;
  S.push(0);
     cout<<"please input!(end of '$')"<<endl;
     cin>>s;
     FENXI();
  if(flag==1)
  {
   cout<<"继续？（继续->输入0；否则输入1）"<<endl;
   cin>>flag;
  }
 }
 system("pause");
 return 0;
}