Cod sursa(job #2641486)

Utilizator NeacsuMihaiNeacsu Mihai NeacsuMihai Data 11 august 2020 16:44:22
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.1 kb
#include <iostream>
#include <fstream>

using namespace std;

ifstream fin ("evaluare.in");
ofstream fout ("evaluare.out");


char s[100002];
int i=0;

int calc();
int termen();
int factor();

int main()
{
    fin>>s;

    fout<<calc();
}

int calc()
{
    int x=termen();

    while(s[i]=='+' || s[i]=='-')
    {
        if(s[i]=='+')
        {
            i++;
            x=x+termen();
        }

        else
        {
            i++;
            x=x-termen();
        }
    }

    i++; // sar peste ')'
    return x;
}

int termen()
{
    int x=factor();

    while(s[i]=='*' || s[i]=='/')
    {
        if(s[i]=='*')
        {
            i++;
            x=x*factor();
        }

        else
        {
            i++;
            x=x/factor();
        }
    }

    return x;
}

int factor()
{
    if(s[i]=='(')
    {
        i++;
        return calc();
    }

    else
    {
        int x=0;

        while(s[i]>='0' && s[i]<='9')
        {
            x=x*10+s[i]-'0';
            i++;
        }

        return x;
    }
}