Cod sursa(job #2379507)

Utilizator capmareAlexCapmare Alex capmareAlex Data 13 martie 2019 19:14:12
Problema Evaluarea unei expresii Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.12 kb
#include <bits/stdc++.h>
#define NMAX 100001
using namespace std;
ifstream fin("evaluare.in");
ofstream fout("evaluare.out");
char s[NMAX],*p=s;

long termen();

long factor();

long eval()
{
    long r=termen();
    while( *p == '+' || *p == '-')
        switch( *p )
    {
        case '+':
        ++p;
        r += termen();
        break;
        case '-':
        ++p;
        r -=termen();
        break;
    }
    return r;
}
long termen()
{
    long r=factor();
    while( *p == '*' || *p == '/')
        switch( *p )
            {
                case '*' :
                    ++p;
                    r*=factor();
                    break;

                case '/' :
                    ++p;
                    r/=factor();
                    break;

            }
    return r;
}
long factor()
{
    long r = 0;
    if(*p == '(' )
    {
        ++p;
        r=eval();
        ++p;
    }
    else while(*p >='0' && *p <= '9')
    {
        r=r*10 + *p - '0';
        ++p;
    }
    return r;
}
int main()
{
    cin.get(s,NMAX);
    cout << eval();
    return 0;
}