Cod sursa(job #2320224)

Utilizator moltComan Calin molt Data 14 ianuarie 2019 15:31:22
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.08 kb
#include <iostream>
#include <fstream>
using namespace std;
ifstream in("evaluare.in");
ofstream out("evaluare.out");
const int N = 100001;
char s[N];
int p;

int expresie();
int termen();
int factor();

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 val = 0,semn = 1;
    while (s[p] == '-')
          {++p;
          semn = -semn;}
    if (s[p] == '(')
        {++p;
        val = expresie();
         ++p;
         return semn * val;}
    while (s[p] >= '0' && s[p] <= '9')
           {val = val * 10 + (s[p] - '0');
           ++p;}
     return semn * val;
}


int main()
{

    in.get(s,N);
    out<<expresie();
    return 0;

}