Cod sursa(job #2922270)

Utilizator victor_gabrielVictor Tene victor_gabriel Data 7 septembrie 2022 16:54:41
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.05 kb
#include <fstream>

using namespace std;

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

const int DIM = 100001;
char s[DIM];
int i = 0;

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

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++;
        r = expresie();
        i++;
    } else {
        r = constanta();
    }
    return r;
}

int constanta() {
    int 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;
}