Cod sursa(job #3209197)

Utilizator UpgradeStrikeMurgilas Mihai-Rares UpgradeStrike Data 2 martie 2024 10:34:04
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.28 kb
#include <fstream>

using namespace std;

const int N = 1e5;

char s[N+1];
int p = 0;

int expresie();
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 val = 0, semn = 1;
    while (s[p] == '-')
    {
        semn = (-semn);
        p++;
    }
    if (s[p] == '(')
    {
        p++;
        val = expresie();
        p++;
        return semn * val;
    }
    while ('0' <= s[p] && s[p] <= '9')
    {
        val = val * 10 + (s[p] - '0');
        p++;
    }
    return semn * val;
}

int main()
{
    ifstream in("evaluare.in");
    ofstream out("evaluare.out");
    in >> s;
    out << expresie() << "\n";
    in.close();
    out.close();
    return 0;
}