Cod sursa(job #3196444)

Utilizator Dia3141Costea Diana Stefania Dia3141 Data 23 ianuarie 2024 21:53:12
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.08 kb
#include <fstream>
using namespace std;
ifstream cin("evaluare.in");
ofstream cout("evaluare.out");
/// evaluarea unei expresii folosind recursivitate indirecta
int i;
char s[100001];
int expresie();
int termen();
int factor();
int constanta();
int expresie(){
    int r=termen();
    while(s[i]=='+'||s[i]=='-'){
        if(s[i]=='+'){
            i++;
            r+=termen();
        }else{
            i++;
            r-=termen();
        }
    }
    return r;
}
int termen(){
    int r=factor();
    while(s[i]=='*'||s[i]=='/'){
        if(s[i]=='*'){
            i++;
            r*=factor();
        }else{
            i++;
            r/=factor();
        }
    }
    return r;
}
int factor(){
    int r;
    if(s[i]=='('){
        i++;
        r=expresie();
        i++; /// sar peste paranteza inchisa
    }else
        r=constanta();
    return r;
}
int constanta(){
    int r=0;
    while(s[i]>='0'&&s[i]<='9'){
        r=r*10+s[i]-'0';
        i++;
    }
    return r;
}
int main()
{
    cin>>s;
    cout<<expresie();
    return 0;
}