Cod sursa(job #1892858)

Utilizator StepHoria Stefan Step Data 25 februarie 2017 12:35:39
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.1 kb
#include <iostream>
#include <fstream>

using namespace std;

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

char s[100001];
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 (s[p]=='*'||s[p]=='/')
    {
        if (s[p]=='*')
        {
            p++;
            prod*=factor();
        }
        if (s[p]=='/')
        {
            p++;
            prod/=factor();
        }
    }
    return prod;
}
int factor()
{
    int val=0,semn=1;
    while (s[p]=='-')
    {
        p++;
        semn=-semn;
    }
    if (s[p]=='(')
    {
        p++;
        val=expresie();
        p++;
        return semn*val;
    }
    while (s[p]>='0'&&s[p]<='9')
    {
        val=val*10+s[p]-'0';
        p++;
    }
    return semn*val;
}
int main()
{
    f.getline(s,100001);
    g<<expresie();
    return 0;
}