Cod sursa(job #1873492)

Utilizator pasoi_stefanPasoi Stefan pasoi_stefan Data 9 februarie 2017 09:43:01
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.79 kb
#include <fstream>
using namespace std;
ifstream f("evaluare.in"); ofstream g("evaluare.out");
char S[100010],*p=S;
int eval();
int factor()
{   int r;
    if(*p=='(') {++p; r=eval(); ++p;}
    else
    {   r=0;
        while(*p>='0' && *p<='9')  {r=r*10+*p-'0'; ++p;}
    }
    return r;
}
int termen()
{   int r=factor();
    while(*p=='*' || *p=='/')
        switch(*p )
        {   case '*' : ++p; r*=factor(); break;
            case '/' : ++p; r/=factor(); break;
        }
    return r;
}
int eval()
{   int r=termen();
    while(*p=='+' || *p=='-')
        switch(*p)
        {   case '+' : ++p; r+=termen(); break;
            case '-' : ++p; r-=termen(); break;
        }
    return r;
}
int main()
{   f>>S;
    g<<eval()<<'\n';
    g.close(); return 0;
}