Cod sursa(job #2190637)

Utilizator DavvDrgDavid Dragostin DavvDrg Data 31 martie 2018 13:20:10
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.97 kb
#include <fstream>

using namespace std;
ifstream fin("evaluare.in");
ofstream fout("evaluare.out");
char s[100002],*p;
int eval();
int termen();
int factor();
int eval()
{
    int r=0;
    r=termen();
    while(*p=='+' || *p=='-')
    {
        if(*p=='+')
        {
            p++;
            r+=termen();
        }
        else
        {
            p++;
            r-=termen();
        }
    }
    return r;
}
int termen()
{
    int r=factor();
    while(*p=='*' || *p=='/')
    {
        if(*p=='*')
        {
            p++;
            r*=factor();
        }
        else
        {
            p++;
            r/=factor();
        }
    }
    return r;
}
int factor()
{
    int r=0;
    if(*p=='(')
    {
        p++;
        r=eval();
        p++;
    }
    else
    {
        while(*p>='0' && *p<='9')
        {
            r=r*10+(int)*p-'0';
            p++;
        }
    }
    return r;
}
int main()
{
    fin.getline(s,100002);
    p=s;
    fout<<eval()<<'\n';
    return 0;
}