Cod sursa(job #1680928)

Utilizator stoicatheodorStt sas stoicatheodor Data 9 aprilie 2016 10:42:32
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.11 kb
#include <fstream>
#include <string.h>
using namespace std;
ifstream in("evaluare.in");
ofstream out("evaluare.out");

char exp[100001], *p = exp;
long long termen();
long long factor();


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


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


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


int main()
{
    in.getline(exp,100001);
    out << eval();
    return 0;
}