Cod sursa(job #1325690)

Utilizator Vali_DeaconuVali Deaconu Vali_Deaconu Data 24 ianuarie 2015 11:38:57
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.03 kb
#include <fstream>

using namespace std;

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

char s[100010];
int i;

int factor();
int termen();

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

int termen() {
    int r;
    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++;
        r = expresie();
        i++;
    } else {
        r = 0;
        while (s[i] >= '0' && s[i] <= '9') {
            r = r * 10 + (s[i] - '0');
            i++;
        }
    }
    return r;
}

int main()
{
    fin >> s;
    fout << expresie();
    return 0;
}