Cod sursa(job #1311443)

Utilizator MihneaGhiraMihnea MihneaGhira Data 8 ianuarie 2015 10:31:56
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1 kb
#include<fstream>
#include<cstring>
using namespace std;
ifstream fin("evaluare.in");
ofstream fout("evaluare.out");
int i;
char s[100010];
int expresie();
int termen();
int factor();

 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();
        }else{
            i++;
            r/=factor();
        }
    }
    return r;
}

int factor(){
    int r=0;
    if(s[i]=='('){
        i++;
        r=expresie();
        i++;
    }else{
        while(s[i]>='0' && s[i]<='9'){
            r*=10;
            r+=s[i]-'0';
            i++;
        }
    }
    return r;
}

int main(){
    fin>>s+1;
    i=1;
    fout<<expresie();
    return 0;
}