Cod sursa(job #1324294)

Utilizator andreeastanescuAndreea Stanescu andreeastanescu Data 22 ianuarie 2015 07:58:29
Problema Evaluarea unei expresii Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 1.02 kb
#include <fstream>
using namespace std;
int expresie ();
int termen();
int factor();
char s[1000002];
int i;
int main (){
    ifstream fin ("evaluare.in");
    ofstream fout ("evaluare.out");
    fin>>s;
    i=0;
    fout<<expresie();
    return 0;
}
int expresie(){
    int r;
    r=termen ();
    while (s[i]=='+'||s[i]=='-'){
        if (s[i]=='+'){
            i++;
            r+=termen();
        }
        else {
            i++;
            r-=termen();
        }
    }
    return r;
}

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

}