Cod sursa(job #1831579)

Utilizator Stefania189StefaniaB Stefania189 Data 18 decembrie 2016 12:24:00
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.89 kb
#include <fstream>
#include <cstring>
using namespace std;
ifstream f("evaluare.in");
ofstream g("evaluare.out");
char s[100010], *p=s;
int eval();
int termen();
int fact();
int eval()
{
    int r=termen();
    while(*p=='+'||*p=='-') {
      if(*p=='+') {
        ++p;
        r+=termen();
      }
      else {
        ++p;
        r-=termen();
      }
    }
    return r;
}
int termen()
{
    int r=fact();
    while(*p=='*'||*p=='/') {
      if(*p=='*') {
        ++p;
        r*=fact();
      }
      else {
        ++p;
        r/=fact();
      }
    }
    return r;
}
int fact()
{
    int 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, 100010);
    g<<eval();
    return 0;
}