Cod sursa(job #2085015)

Utilizator patcasrarespatcas rares danut patcasrares Data 9 decembrie 2017 15:45:30
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.17 kb
#include<fstream>
#include<cmath>
#include<iostream>
#define DN 100005
#include<vector>
#include<cctype>
#include<cstring>
using namespace std;
ifstream fin("evaluare.in");
ofstream fout("evaluare.out");
int ev();
int termen();
int factor();
int poz;
char a[DN];
int ev()
{
    int r=0;
    r=termen();
    while(a[poz]=='+'||a[poz]=='-')
    {
        if(a[poz]=='+')
        {
            poz++;
            r+=termen();
        }
        else
            {
                poz++;
                r-=termen();
            }
    }
    return r;
}
int termen()
{
    int r=0;
    r=factor();
    while(a[poz]=='*'||a[poz]=='/')
    {
        if(a[poz]=='*')
        {
            poz++;
            r*=factor();
        }
        else
            {
                poz++;
                r/=factor();
            }
    }
    return r;
}
int factor()
{
    int r=0;
    if(a[poz]=='(')
    {
        poz++;
        r=ev();
        poz++;
    }
    else
        while(isdigit(a[poz]))
        {
            r=r*10+(a[poz]-'0');
            poz++;
        }
    return r;
}
int main()
{
    fin.getline(a,DN);
    fout<<ev();
}