Cod sursa(job #1635457)

Utilizator RaZxKiDDavid Razvan RaZxKiD Data 6 martie 2016 17:53:39
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.12 kb
#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;

ifstream in("evaluare.in");
ofstream out("evaluare.out");

char C[100002];
int x=0;
int eval();
int termen();
int factor();
int to_int(){
    int r=0;
    while(isdigit(C[x])){
        r*=10;
        r+=C[x]-'0';
        x++;
    }
    return r;
}
int eval(){
    int r=termen();
    while(C[x]=='+'||C[x]=='-'){
        if(C[x]=='+'){
            x++;
            r+=termen();
        }
        else if(C[x]=='-'){
            x++;
            r-=termen();
        }
    }
    return r;
}
int termen(){
    int r=factor();
    while(C[x]=='*'||C[x]=='/'){
        if(C[x]=='*'){
            x++;
            r*=factor();
        }
        else if(C[x]=='/'){
            x++;
            r/=factor();
        }
    }
    return r;
}
int factor(){
    int r=0;
    if(C[x]=='('){
        x++; /// se sare )
        r=eval();
        x++; /// se sare )
    }
    else{
        r=to_int();
    }
    return r;
}
int main(){
    int rez=0;
    int semn;
    in>>C;
    out<<eval();
    return 0;
}