Cod sursa(job #2026991)

Utilizator StefanTufisTufis Stefan StefanTufis Data 25 septembrie 2017 14:24:01
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.02 kb
#include <fstream>
using namespace std;
ifstream f("evaluare.in");
ofstream g("evaluare.out");
int n;
char s[100001],*p=s;
long termen();
long factor();
long eval()
{
    long r=termen();
    while(*p=='+' || *p=='-')
        if (*p=='+')
        {
            p++;
            r=r+termen();
        }
        else if(*p=='-')
        {
            p++;
            r=r-termen();
        }
        return r;
}
long termen()
{
    long r=factor();
     while ( *p=='*' or *p=='/' )
     {
         if(*p=='*' )
         {
             p++;
             r=r*factor();

         }
         else if (*p=='/')
         {
             p++;
             r=r/factor();

         }

     }
    return r;
}
long factor()
{
    long r=0;
    if(*p=='(')
    {
        p++;
        r=eval();
        p++;
    }
    else while(*p>='0' && *p<='9')
    {
        r=r*10+(*p-'0');
        p++;
    }
    return r;
}
int main()
{
    f.getline(s,100001);
    g<<eval();
    return 0;
}