Cod sursa(job #2171337)

Utilizator cristiancristea_2010Cristian Cristea cristiancristea_2010 Data 15 martie 2018 11:58:54
Problema Evaluarea unei expresii Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 1.1 kb
#include <iostream>
#include <fstream>
using namespace std;
ifstream f("evaluare.in");
ofstream g("evaluare.out");
char s[100010],*p=s;

long termen();
long factor();

long eval()
{
    long r=termen();
    while (*p=='+' || *p=='-')
    {
        if (*p=='+')
        {
            ++p;
            r=r+termen();
            break;
        }
        else
        {
            ++p;
            r=r-termen();
            break;
        }
    }
    return r;
}

long termen()
{
    long r=factor();
    while (*p=='*' || *p=='/')
    {
        if (*p=='*')
        {
            ++p;
            r=r*factor();
            break;
        }
        else
        {
            ++p;
            r=r/factor();
            break;
        }
    }
    return r;
}

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

int main()
{
    f.get(s,100010);
    g<<eval();
}