Cod sursa(job #1846325)

Utilizator mariusn01Marius Nicoli mariusn01 Data 12 ianuarie 2017 16:02:37
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.16 kb
#include <fstream>

using namespace std;
char s[100100];
int i;
int expresie();
int factor();
int termen();

int expresie () {
    int r = termen();
    while (s[i] == '+' || s[i] == '-') {
        if (s[i] == '+') {
            i++;
            r += termen();
        } else {
            i++;
            r -= termen();
        }
    }
    return r;
}

int termen() {
    int r = factor();
    while (s[i] == '*' || s[i] == '/') {
        if (s[i] == '*') {
            i++;
            r *= factor();
        } else {
            i++;
            r /= factor();
        }
    }
    return r;
}

int factor() {
    int r;
    if (s[i] == '(') {
        i++; // salt peste paranteza deschisa
        r = expresie();
        i++; // salt peste paranteza inchisa
    } else {
        // sigur este o valoare
        r = 0;
        while (s[i] >= '0' && s[i] <= '9') {
            r = r * 10 + s[i]-'0';
            i++;
        }
    }
    return r;

}

ifstream fin ("evaluare.in");
ofstream fout("evaluare.out");

int main () {
    fin>>s;
    i = 0; // pozitia primului caracter
    fout<<expresie();

    return 0;
}