Cod sursa(job #2556836)

Utilizator Bulboaca_EugenBulboaca Alexandru Eugen Bulboaca_Eugen Data 25 februarie 2020 10:56:29
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.06 kb
#include <bits/stdc++.h>
using namespace std;
ifstream fin("evaluare.in");
ofstream fout("evaluare.out");
const int MAXN = 1 * 1e5 + 5;
char sir[MAXN], *p = sir;
long long termen();
long long factor();
long long eval(){
    long long r = termen();
    while(*p == '+' || *p == '-'){
        if(*p == '+'){
            ++p;
            r += termen();
        }
        else if(*p == '-'){
            ++p;
            r -= termen();
        }
    }
    return r;
}
long long termen(){
    long long r = factor();
    while(*p == '*' || *p == '/'){
        if(*p == '*'){
            ++p;
            r *= factor();
        }
        else if(*p == '/'){
            ++p;
            r /= factor();
        }
    }
    return r;
}
long long factor(){
    long long r = 0;
    if(*p == '('){
        ++p;
        r = eval();
        ++p;
    }
    else{
        while(*p <= '9' and *p >= '0')
            r = r * 10 + *p - '0', ++p;
    }
    return r;
}
int main()
{
    fin.getline(sir, MAXN);
    fout << eval();
    return 0;
}