Cod sursa(job #2163175)

Utilizator PopeangaMihneaPopeanga Mihnea- Stefan PopeangaMihnea Data 12 martie 2018 17:00:35
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.08 kb
#include <bits/stdc++.h>

using namespace std;

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

char s[100001];
int i;

int eval();
int termen();
int fact();

int main()
{
    fin.getline(s, 100001);
    i=0;
    fout<<eval();
    return 0;
}

int eval()
{
    int r=termen();
    while(s[i]=='+' || s[i]=='-')
    {
        if(s[i]=='+')
        {
            ++i;
            r=r+termen();
        }
        else
        {
            ++i;
            r=r-termen();
        }
    }
    return r;
}

int termen()
{
    int r=fact();
    while(s[i]=='*' || s[i]=='/')
    {
        if(s[i]=='*')
        {
            ++i;
            r=r*fact();
        }
        else
        {
            ++i;
            r=r/fact();
        }
    }
    return r;
}

int fact()
{
    int r=0;
    if(s[i]=='(')
    {
        ++i;
        r=eval();
        ++i;
    }
    else
    {
        r=0;
        while(s[i]>='0' && s[i]<='9')
        {
            r=r*10+s[i]-'0';
            ++i;
        }
    }
    return r;
}