Cod sursa(job #2109306)

Utilizator ale.sicobeanAlexandra Sicobean ale.sicobean Data 19 ianuarie 2018 16:07:36
Problema Evaluarea unei expresii Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.19 kb
#include <iostream>
#include <fstream>
#include <string.h>
#include <stack>
using namespace std;
ifstream fin("eval.in");
ofstream fout("eval.out");
string s;
int x;
int is_op1(int ind)
{
    if(s[ind]=='+' || s[ind]=='-')
        return 1;
    else
        return 0;
}

int is_op2(int ind)
{
    if(s[ind]=='*' || s[ind]=='/')
        return 1;
    else
        return 0;
}
int factor(int &ind)
{
    int eval(int &a);
    int nr=0;
    if(s[ind]=='(')
    {
        int nr=eval(++ind);
        ind++;
        return nr;
    }
    else
    while(ind<=s.size() && isdigit(s[ind])!=0)
    {
        nr=nr*10+s[ind]-'0';
        ind++;
    }
    return nr;
}
int termen(int &ind)
{
    int p=factor(ind);
    while(ind<=s.size() && is_op2(ind))
    {
        if(s[ind]=='*')
            p*=factor(++ind);
        else
            p/=factor(++ind);
    }
    return p;
}
int eval(int &ind)
{
    int a;
    a=termen(ind);
    while(ind<=s.size() && is_op1(ind))
    {
        if(s[ind]=='+')
            a+=termen(++ind);
        else
            a-=termen(++ind);
    }
    return a;
}
int main()
{
    fin>>s;
    fout<<eval(x);
    return 0;
}