Cod sursa(job #2115745)

Utilizator elenaisaiaElena Isaia elenaisaia Data 27 ianuarie 2018 09:39:45
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.15 kb
#include <iostream>
#include <fstream>
#include <cstring>

using namespace std;

char s[100005];
int n,i;

long long termen();
long long factor();

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

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

long long factor()
{
    long long r=0;
    if(s[i]=='(')
    {
        i++;
        r=eval();
        i++;
    }
    else
    {
        while(s[i]>='0'&&s[i]<='9')
        {
            r=r*10+(s[i]-48);
            i++;
        }
    }
    return r;
}

int main()
{
    ifstream fin("evaluare.in");
    ofstream fout("evaluare.out");
    fin.getline(s,100005);
    n=strlen(s);
    fout<<eval();
    return 0;
}