Cod sursa(job #2705185)

Utilizator opreamara22Oprea Mara Sonia opreamara22 Data 12 februarie 2021 09:08:28
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.17 kb
#include <fstream>

using namespace std;
ifstream cin("evaluare.in");
ofstream cout("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 val=0,semn=1;
    while(s[p]=='-')
    {
        p++;
        semn=-semn;
    }
    if(s[p]=='(')
    {
        p++;
        val=expresie();
        p++;
        return semn*val;
    }
    while('0'<=s[p] && s[p]<='9')
    {
        val=val*10 + (s[p]-'0');
        p++;
    }
    return semn*val;
}

int main()
{
    cin>>s;
    cout<<expresie();
    return 0;
}