Cod sursa(job #1570472)

Utilizator RazvanatorHilea Razvan Razvanator Data 16 ianuarie 2016 16:06:56
Problema Evaluarea unei expresii Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 1.13 kb
#include <iostream>
#include <fstream>
#include <string.h>

using namespace std;

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

char s[100000];
int p;

int expresie();
int termen();
int factor();

int expresie()
{
    int sum=termen();
    while (s[p]=='+' || s[p]=='-') {
        if (s[p]=='+') {
            p++;
            sum+=termen();
        }
        else {
            p++;
            sum-=termen();
        }
    }
    return sum;
}

int termen()
{
    int prod=factor();
    while (prod=='*' || prod=='/') {
        if (prod=='*') {
            p++;
            prod*=factor();
        }
        else {
            p++;
            prod/=factor();
        }
    }
    return prod;
}

int factor()
{
    int semn=1,val=0;
    while (s[p]=='-') {
        p++;
        semn=-semn;
    }
    if (s[p]=='(') {
            p++;
            expresie();
            p++;
            return val*semn;
    }
    while (s[p]>='0' && s[p]<='9') {
        val=val*10+s[p]-'0';
        p++;
    }
    return semn*val;
}
int main()
{
    f.get(s,100000);
    g<<expresie();
}