Cod sursa(job #2042890)

Utilizator RaduXD1Nicolae Radu RaduXD1 Data 19 octombrie 2017 12:45:45
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.08 kb
#include <fstream>

using namespace std;
ifstream fin ("evaluare.in");
ofstream fout("evaluare.out");
char s[100002];
int i;
int expresie(), termen(),factor();

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=0;
    if(s[i]=='(')
    {
        i++;
        r=expresie();
        i++;
    }
    else
        while(s[i]>='0'&&s[i]<='9')
        {
            r*=10;
            r+=s[i]-'0';
            i++;
        }
    return r;
}


int main(){
    fin>>s;
    i=0;
    fout<<expresie();
    fin.close();
    fout.close();
    return 0;
}