Cod sursa(job #748907)

Utilizator vladstoickvladstoick vladstoick Data 15 mai 2012 09:22:47
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.1 kb
#include<fstream>
using namespace std;
ifstream in("evaluare.in");
ofstream out("evaluare.out");
const int N= 100001;
int p;
char s[N];
int factor();
int termen();
int expresie();
int factor()
{
    int val=0,semn=1;
    while(s[p]=='-')
        semn=-semn;
    if(s[p]=='(')
    {
        p++;
        val=expresie();
        p++;
        return semn*val;
    }
    while(s[p]>='0')
    {
        val=val*10+s[p]-(int)'0';
        p++;
    }
    return semn*val;
}
int termen()
{
    int prod=factor();
    while(s[p]=='*' || s[p]=='/')
    {
        if(s[p]=='*')
        {
            p++;
            prod*=factor();
        }
        else
        {
            p++;
            prod/=factor();
        }
    }
    return prod;
}
int expresie()
{
    int sum=termen();
    while(s[p]=='+' || s[p]=='-')
    {
        if(s[p]=='+')
        {
            p++;
            sum+=termen();
        }
        else
        {
            p++;
            sum-=termen();
        }
    }
    return sum;
}

int main()
{
    in.getline(s,N);
    out<<expresie();
}