利用栈做行编辑器

问题来源http://hi.baidu.com/frankxieke/item/d8536acf63e1a57f89ad9eb8

#include<stdlib.h>
 #include<stdio.h> 
 #include<string.h>
 #include<iostream>
using namespace std;
 #define TRUE 1
 #define FALSE 0
 #define OK 1
 #define ERROR 0
 #define INFEASIBLE -1
 #define OVERFLOW -2
 
 typedef char Status;
 typedef char SElemType;
 #define STACK_INIT_SIZE 100
 #define STACKINCREMENT 10
 typedef struct{
         SElemType *base;
         SElemType *top;
         int stacksize;
         }SqStack;
 
 Status InitStack(SqStack &S){
        S.base = (SElemType * )malloc(STACK_INIT_SIZE * sizeof(SElemType));
        if(!S.base) exit(OVERFLOW);
        S.top = S.base;
        S.stacksize=STACK_INIT_SIZE;
        return OK;
        }//InintStack
 Status GetTop(SqStack S,SElemType &e){
        if(S.top==S.base) return ERROR;
        e=*(S.top-1);
        return OK;
        }//GrtTop
 Status Push(SqStack &S,SElemType e){
        if(S.top-S.base>=S.stacksize){
        S.base=(SElemType*)realloc(S.base,(S.stacksize+STACKINCREMENT)*sizeof(SElemType));
        if(!S.base) exit(OVERFLOW);
        S.top=S.base+S.stacksize;
        S.stacksize+=STACKINCREMENT;
        }
        *S.top++=e;
        return OK;
        }//Push
 Status Pop(SqStack &S,SElemType &e){
        if(S.top==S.base) {e = -1;return ERROR;}
        e=*--S.top;
        return OK;
        }//Pop
 Status ClearStack(SqStack &S){
        S.top=S.base;
        return OK;
        }//ClearStack
 Status DestroyStack(SqStack &S){
        S.top=0;
        return OK;
        }
 void LineEdit(){
      SqStack S;
      InitStack(S);
      char ch;
      ch=getchar();
      while(ch!=EOF){
                     while(ch!=EOF&&ch!='\n'){
                     switch(ch){
                                case '#': 
                                     {
                                          Pop(S,ch); 
                                          if(ch != -1)
                                          cout << "pop success: " << ch << endl;
                                          else 
                                          cout << "pop error : stack empty " << endl;
                                          break;
                                     }
                                case '@': 
                                     {
                                          ClearStack(S);
                                          cout << "clear success" << endl;
                                           break;
                                     }
                                default : 
                                        {
                                                 Push(S,ch);
                                                 cout << "push success: " << ch << endl;
                                                  break;
                                        }
                                }
                                ch=getchar();
                     }
                     if(S.top != 0)ClearStack(S);
                     ch = getchar();                    
      } 
      DestroyStack(S);
}
 
 int main()
 {
       LineEdit();
       return 0;
 }