Cod sursa(job #1875632)

Utilizator medicinedoctoralexandru medicinedoctor Data 11 februarie 2017 13:23:46
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.75 kb
#include <fstream>

using namespace std;

ifstream cin("evaluare.in");
ofstream cout("evaluare.out");

string s;
int i=0;

int prod();
int term();

int eval()
{
    int r=prod();
    while (i<s.size() && (s[i]=='+' || s[i]=='-'))
    {
        i++;
        if (s[i-1]=='+') r+=prod(); else r-=prod();
    }
    return r;
}

int prod()
{
    int r=term();
    while (i<s.size() && (s[i]=='*' || s[i]=='/'))
    {
        i++;
        if (s[i-1]=='*') r*=term(); else r/=term();
    }
    return r;
}

int term()
{
    int r=0;
    if (s[i]=='(')
        i++,r=eval(),i++;
    else
    while (i<s.size() && (s[i]<='9' && s[i]>='0'))
        r=r*10+s[i]-'0',i++;
    return r;
}

main()
{
    cin >> s;
    cout << eval();
}