Cod sursa(job #1481369)

Utilizator NicolaalexandraNicola Alexandra Mihaela Nicolaalexandra Data 4 septembrie 2015 12:28:47
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.03 kb
#include <fstream>

using namespace std;

char s[100003];

int i;

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

int expresie();
int termen();
int factor();

int main (){

    fin>>s;
    i = 0;
    fout<<expresie();
    return 0;
}


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