Cod sursa(job #2700946)

Utilizator MenelausSontea Vladimir Menelaus Data 29 ianuarie 2021 12:52:35
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.21 kb
#include <iostream>
#include <fstream>

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

const int N=100000;
static char s[N+1];
int p=0;

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

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

    return sum;
}

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

    return prod;

}

int factor()
{
    int semn=1;
    int val=0;

    if(s[p]=='-')
    {
        semn*=-1;
        p++;
    }

    if(s[p]=='(')
    {
        p++;
        val=expresie();
        p++;
        return semn*val;
    }

    while(isdigit(s[p]))
    {
        val=val*10+(s[p++]-'0');
    }
    return semn*val;
}

int main()
{
    in.getline(s, N+1);
    out<<expresie();
    return 0;
}