Cod sursa(job #1324300)

Utilizator teodoracrivineanuTeodora Crivineanu teodoracrivineanu Data 22 ianuarie 2015 08:14:19
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.03 kb
#include<iostream>
#include<fstream>
using namespace std;
ifstream fin("evaluare.in");
ofstream fout("evaluare.out");
char s[100002];
int i;
int expresie();
int factor();
int termen();
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 termen() {
    int p;
    p=factor();
    while((s[i]=='*')||(s[i]=='/')){
        if(s[i]=='*'){
            i++;
            p=p*factor();
        }
        else{
            i++;
            p=p/factor();
        }
    }
    return p;
}
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 main (){
    fin>>s;
    i=0;
    fout<<expresie();
    return 0;
}