Cod sursa(job #1844635)

Utilizator raduzxstefanescu radu raduzx Data 10 ianuarie 2017 10:50:13
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.05 kb
#include <fstream>
using namespace std;
ifstream f("evaluare.in");
ofstream g("evaluare.out");
char s[100004],*p;
#define nmax 100004;
typedef long long ll;
ll eval();
ll termen();
ll factor();

ll eval()
{
    ll r=termen();
    while(*p=='+' or *p=='-')
    {
        if(*p=='+')
        {
            p+=1;
            r+=termen();
        }
        else
        {
            p+=1;
            r-=termen();
        }
    }
    return r;
}
ll termen()
{
    ll r=factor();
    while(*p=='*' or *p=='/')
    {
        if(*p=='*')
        {
            p+=1;
            r*=factor();
        }
        else
        {
            p+=1;
            r/=factor();
        }
    }
    return r;
}

ll factor()
{
    long r=0;
    if(*p=='(')
    {
        p+=1;
        r=eval();
        p+=1;
    }
    else
    {
        while(*p>='0' and *p<='9')
        {
            r=r*10+*p-'0';
            p+=1;
        }
    }
    return r;

}
int main()
{
    f>>s;
    p=s;
    g<<eval();
    return 0;
}