Cod sursa(job #1062936)

Utilizator acomAndrei Comaneci acom Data 21 decembrie 2013 10:40:24
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.01 kb
#include<fstream>
using namespace std;
ifstream f("evaluare.in");
ofstream g("evaluare.out");
int i;
char s[100005];
int expresie();
int termen();
int factor();
int main()
{
    f.getline(s,100005);
    g<<expresie()<<'\n';
    return 0;
}
int expresie()
{
    int r=termen();
    while (s[i]=='+' || s[i]=='-')
    {
        if (s[i]=='+')
        {
            ++i;
            r+=termen();
        }
        else
        {
            ++i;
            r-=termen();
        }
    }
    return r;
}
int termen()
{
    int r=factor();
    while (s[i]=='*' || s[i]=='/')
    {
        if (s[i]=='*')
        {
            ++i;
            r*=factor();
        }
        else
        {
            ++i;
            r/=factor();
        }
    }
    return r;
}
int factor()
{
    int r=0;
    if (s[i]=='(')
    {
        ++i;
        r=expresie();
        ++i;
    }
    else while ('0'<=s[i] && s[i]<='9')
    {
        r=r*10+s[i]-'0';
        ++i;
    }
    return r;
}