Cod sursa(job #2812858)

Utilizator rares89_Dumitriu Rares rares89_ Data 5 decembrie 2021 12:37:09
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.95 kb
#include <fstream>

using namespace std;

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

string s;
int i;

int expr();

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

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

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

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