Cod sursa(job #2676647)

Utilizator bibiancapitu2004Pitu Bianca bibiancapitu2004 Data 24 noiembrie 2020 18:42:45
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.16 kb
#include <fstream>
using namespace std;
ifstream in("evaluare.in");
ofstream out("evaluare.out");

const int N = 100000;
char s[N + 1];
int expresie();
int factor();
int termen();
int p;

int expresie()
{
int sum = termen();
 while(s[p] == '+' || s[p] == '-')
  {
    if(s[p] == '+')
    {
      p ++;
      sum += termen();
    }
    else
    {
       p ++;
       sum -= termen();
    }
  }
  return sum;
}
int termen()
{
    int prod = factor();
    while(s[p] == '*'||s[p] == '/')
    {
        if(s[p] == '*')
        {
            p++;
            prod *= factor();
        }
        else
        {
            p ++;
            prod /= factor();
        }
    }
    return prod;
}
int factor()
{
    int sign = 1,val = 0;
    while(s[p] == '-')
    {
        p ++;
        sign = -sign;
    }
    if(s[p] == '(')
    {
        p ++;
        val = expresie();
        p ++;
        return sign * val;
    }
    else while(s[p] >= '0' && s[p] <= '9')
    {
        val = val * 10 + (s[p] - '0');
        p ++;
    }
    return sign * val;
}

int main()
{
    in >> s;
    out << expresie();
    return 0;
}