Cod sursa(job #1823297)

Utilizator stefanidisstefan27Stefanidis Stefan stefanidisstefan27 Data 6 decembrie 2016 10:22:02
Problema Evaluarea unei expresii Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.08 kb
#include <fstream>

using namespace std;
ifstream in("evaluare.in");
ofstream out("evaluare.out");

const int N=100001;
char s[N];
int p=0;
int expresie();
int termen();
int factor();

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

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

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

int main()
{
    in.getline(s,N);
    out<<expresie();
    return 0;
}