Cod sursa(job #1257353)

Utilizator ovidiuz98Zamfir Ovidiu ovidiuz98 Data 7 noiembrie 2014 17:28:03
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.04 kb
#include <fstream>

using namespace std;
ifstream fin("evaluare.in");
ofstream fout("evaluare.out");
char s[100002];
int i;

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=0;
    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;
    i=0;
    fout<<expresie();
    fin.close();fout.close();
    return 0;
}