Cod sursa(job #876741)

Utilizator pauldinudinu paul pauldinu Data 12 februarie 2013 08:03:33
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.18 kb
#include <fstream>

using namespace std;

char s[100001];
int p;

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 semn=1,val=0;
    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;
}
ifstream f("evaluare.in");
ofstream g("evaluare.out");
int main()
{
    //cout << "Hello world!" << endl;
    f.getline(s,100001);
    g<<expresie();
    return 0;
}