Cod sursa(job #2415671)

Utilizator andreisontea01Andrei Sontea andreisontea01 Data 26 aprilie 2019 13:44:50
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.1 kb
#include <bits/stdc++.h>

using namespace std;

string s;
int eval();
int termen();
int factor();
int p;

int eval(){
    int val = termen();
    while(s[p] == '+' || s[p] == '-'){
        if(s[p] == '+'){
            p++;
            val += termen();
        }
        else{
            p++;
            val -= termen();
        }
    }
    return val;
}

int termen(){
    int val = factor();
    while(s[p] == '*' || s[p] == '/'){
        if(s[p] == '*'){
            p++;
            val *= factor();
        }
        else{
            p++;
            val /= factor();
        }
    }
    return val;
}

int factor(){
    int semn = 1, val = 0;
    while(s[p] == '-'){
        semn = -semn;
        p++;
    }
    if(s[p] == '('){
        p++;
        val = eval();
        p++;
        return val * semn;
    }
    while(isdigit(s[p])){
        val = val * 10 + s[p] - '0';
        p++;
    }
    return val * semn;
}

int main()
{
    ifstream fin("evaluare.in");
    ofstream fout("evaluare.out");
    getline(fin, s);
    fout << eval();
    return 0;
}