Cod sursa(job #2676056)

Utilizator CalinRadoiRadoi Calin CalinRadoi Data 23 noiembrie 2020 12:20:53
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.2 kb
#include <iostream>
#include <fstream>

using namespace std;

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

const int N = 100000;

char s[N+1];

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();
        }
        else
        {
            p++;
            prod/=factor();
        }
    }
    return prod;
}
int factor()
{
    int semn = 1, val=0;
    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()
{
    in>>s;
    out<<expresie();
    return 0;
}