Cod sursa(job #1324299)

Utilizator arstefAchim Raluca arstef Data 22 ianuarie 2015 08:05:52
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.01 kb
#include<fstream>
using namespace std;
int expresie ();
int termen ();
int factor ();
ifstream fin("evaluare.in");
ofstream fout("evaluare.out");
int i;
char s[100002];
int expresie() {
    int r;
    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;
    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;
    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;
}


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