Cod sursa(job #1733972)

Utilizator triscacezarTrisca Vicol Cezar triscacezar Data 26 iulie 2016 11:26:20
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.99 kb
#include <fstream>

using namespace std;
ifstream f("evaluare.in");
ofstream g("evaluare.out");
int i,S(),P(),B(),N();
char e[100010];
int main()
{
    f>>e;
    g<<S();
    return 0;
}
int S()
{
    int ret=P();
    while(e[i]=='+'||e[i]=='-')
    {
        if(e[i]=='+')
        {
            i++;
            ret+=P();
        }
        else
        {
            i++;
            ret-=P();
        }
    }
    return ret;
}
int P()
{
    int ret=B();
    while(e[i]=='*'||e[i]=='/')
    {
        if(e[i]=='*')
        {
            i++;
            ret*=B();
        }
        else
        {
            i++;
            ret/=B();
        }
    }
    return ret;
}
int B()
{
    int ret;
    if(e[i]=='(')
    {
        i++;
        ret=S();
        i++;
    }
    else
        ret=N();
    return ret;
}
int N()
{
    int ret=0;
    while('0'<=e[i]&&e[i]<='9')
    {
        ret=10*ret+e[i]-'0';
        i++;
    }
    return ret;
}