Cod sursa(job #2103492)

Utilizator PopeangaMihneaPopeanga Mihnea- Stefan PopeangaMihnea Data 10 ianuarie 2018 13:21:22
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.11 kb
#include <iostream>
#include <fstream>

using namespace std;

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

int expresie();
int termen();
int factor();

char s[100010];;
int i;

int main()
{
    fin>>s;
    i=0;
    fout<<expresie()<<"\n";
    return 0;
}

int expresie()
{
    int r=termen();
    while(s[i]=='+' || s[i]=='-')
    {
        if(s[i]=='+')
        {
            ++i;
            r=r+termen();
        }
        else
        {
            ++i;
            r=r-termen();
        }
    }
    return r;
}

int termen()
{
    int r=factor();
    while(s[i]=='*' || s[i]=='/')
    {
        if(s[i]=='*')
        {
            ++i;
            r=r*factor();
        }
        else
        {
            ++i;
            r=r/factor();
        }
    }
    return r;
}

int factor()
{
    int r=0;
    if(s[i]=='(')
    {
        ++i;
        r=expresie();
        ++i;
    }
    else
    {
        r=0;
        while(s[i]>='0' && s[i]<='9')
        {
            r=r*10+(s[i]-'0');
            ++i;
        }
    }
    return r;
}