Cod sursa(job #2357067)

Utilizator Luca19Hritcu Luca Luca19 Data 27 februarie 2019 09:21:02
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.18 kb
#include <iostream>
#include <fstream>
using namespace std;
ifstream f ("evaluare.in");
ofstream g ("evaluare.out");
const int N=100001;
char s[N];
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]=='-')
    {
        semn=-semn;
        p++;
    }
    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>>s;
    g<<expresie();
    return 0;
}