Cod sursa(job #1020479)

Utilizator iordache.bogdanIordache Ioan-Bogdan iordache.bogdan Data 2 noiembrie 2013 09:53:52
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.08 kb
#include <fstream>
using namespace std;

char s[100010];
int i;

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


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;
    if(s[i]=='(')
    {
        i++;
        r=expresie();
        i++;
    }
    else
    {
        r=0;
        while(s[i]>='0' && s[i]<='9')
        {
            r=r*10+s[i]-'0';
            i++;
        }

    }
    return r;
}



int main()
{
    ifstream f("evaluare.in");
    ofstream g("evaluare.out");
    f>>s;
    g<<expresie();
    f.close();
    g.close();
    return 0;
}