Cod sursa(job #2072263)

Utilizator jumareastefanstefan jumarea jumareastefan Data 21 noiembrie 2017 17:20:44
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.81 kb
#include <iostream>
#include <fstream>

using namespace std;

char s[100001], *p;

ifstream f("evaluare.in");
ofstream g("evaluare.out");

int eval();
int term();
int fact();

int main()
{
    f.getline(s, 100000);
    p=s;
    g<<eval();
}

int eval()
{
    int r=term();
    while (*p=='+' || *p=='-')
    {
        if (*p=='+'){++p; r=r+term();}
        else {++p; r=r-term();}
    }
    return r;
}

int term()
{
    int r=fact();
    while (*p=='*' || *p=='/')
    {
        if (*p=='*'){++p; r=r*fact();}
        else {++p; r=r/fact();}
    }
    return r;
}

int fact()
{
    int r=0;
    if (*p=='('){p++;
                r=eval();
                p++;}
    else
        while (*p>='0' && *p<='9')
    {
        r=r*10+(int)*p-'0';
        p++;
    }
    return r;
}