Cod sursa(job #3213506)

Utilizator GabrielPopescu21GabrielPopescu21 GabrielPopescu21 Data 13 martie 2024 10:45:54
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.27 kb
#include <bits/stdc++.h>
using namespace std;

#define cin in
#define cout out

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

char s[100001];
int i, n;
int expresie();
int termen();
int factor();
int constanta();

int main()
{
    cin >> s;
    n = strlen(s);
    cout << expresie();
    return 0;
}

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

int termen()
{
    int ans = factor();
    while (i < n && s[i] == '*' || s[i] == '/')
    {
        if (s[i] == '*')
        {
            ++i;
            ans *= factor();
        }
        else
        {
            ++i;
            ans /= factor();
        }
    }
    return ans;
}

int factor()
{
    int r;
    if (s[i] == '(')
    {
        ++i;
        r += expresie();
        ++i;
    }
    else
        r = constanta();
    return r;
}

int constanta()
{
    int number = 0;
    while (i < n && isdigit(s[i]))
    {
        number = number * 10 + s[i] - '0';
        ++i;
    }
    return number;
}