Cod sursa(job #2676045)

Utilizator ttttDumitru Andrei Denis tttt Data 23 noiembrie 2020 12:08:16
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.17 kb

#include <fstream>

using namespace std;

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()
{
    ifstream cin("evaluare.in");
    ofstream cout("evaluare.out");
    cin>>s;
    cout<<expresie();
}