tyvj1041 表达式求值

链接网址:http://tyvj.cn/Problem_Show.asp?id=1041

#include
#include
#include
#include
#include
using namespace std;
const int MAX=1505;
char sum1[MAX],sum2[MAX];
int a[MAX];
string str;

string addion(string s1,string s2)  
{   int i,j;  
    memset(sum1,0,sizeof(sum1));  
    memset(sum2,0,sizeof(sum2));  
    for(j=0,i=s1.length()-1;i>=0;i--)  
        sum1[j++]=s1[i]-'0';  
    for(j=0,i=s2.length()-1;i>=0;i--)  
        sum2[j++]=s2[i]-'0';  
    for(i=0;i=10 )   
        {   sum1[i]-=10;  
            sum1[i+1]++;   
        }  
    }  
    string s="";    
    for(i=MAX;(i>=0)&&(sum1[i]==0);i--) ;  
    if(i>=0)  
    for(;i>=0;i--)  s+=sum1[i]+'0';  
    else s="0";  
    return s;  
}  
string sub(string s3,string s4)//减法运算    
{   int i,j,flag=1;  
    string s5="";  
    memset(sum1,0,sizeof(sum1));  
    memset(sum2,0,sizeof(sum2));  
    //if((s4.length()>s3.length())||(s4.length()==s3.length()&&s3.compare(s4)<0))//当被减数大于减数的时候交换两个字符串,且应该放在赋值前面    
    //{ swap(s3,s4);  
    //  flag=0;  
    //}  
    for(i=s3.length()-1,j=0;i>=0;i--)  
      sum1[j++]=int(s3[i]-'0');  
    for(i=s4.length()-1,j=0;i>=0;i--)  
      sum2[j++]=int(s4[i]-'0');  
    //cout<=sum2[i]) sum1[i]-=sum2[i];  
      else  
      {  sum1[i]-=sum2[i]-10;  
         sum1[i+1]-=1;   
      }  
    }  
    for(i=MAX;i>=0&&sum1[i]==0;i--);  
   // if(!flag) s5="-";  
    if(i>=0)  
      for(;i>=0;i--)  
         s5+=sum1[i]+'0';  
    else s5="0";  
    return s5;  
}
 
int main()
{
    int l,i,t=0,k;
    //cout<>str){
        l=str.length();
        for(i=0;i>s1;
        sum=s1;
        k=0;
        while(in>>s){            
            if(a[k]==0) sum=addion(sum,s);
            if(a[k]==1) sum=sub(sum,s);
            k++;
        } 
        cout<