Cod sursa(job #1491804)

Utilizator elevenstrArina Raileanu elevenstr Data 26 septembrie 2015 10:28:47
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.12 kb
#include <fstream>
using namespace std;
ifstream fin("evaluare.in");
ofstream fout("evaluare.out");
#define MAX 100008
int expresie();
int termen();
int factor();
char s[MAX];
int poz=1;
int main()
{
    int n,i,j;
    fin.getline(s+1,MAX);
    fout<<expresie();

    return 0;
}
int expresie()
{
    int ans=termen();
    while(s[poz]=='+'||s[poz]=='-')
        if(s[poz]=='+')
        {
            poz++;
            ans=ans+termen();

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

        }
        else
        {
            poz++;
            ans=ans/factor();
        }
    return ans;
}

int factor()
{
    int ans=0;
    if(s[poz]=='(')
    {
        poz++;
        ans=expresie();
        poz++;
    }

    else
        while(s[poz]>='0'&&s[poz]<='9')
        {
            ans=ans*10+s[poz]-'0';
            poz++;
        }
    return ans;
}