Cod sursa(job #2677702)

Utilizator ZelenacChristianZelenac Christian ZelenacChristian Data 27 noiembrie 2020 10:57:22
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.2 kb
#include <iostream>
#include <fstream>
#include <cctype>

using namespace std;

const int N=100001;

char s[N];

int p;
int termen();
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()
{
    ifstream in("evaluare.in");
    ofstream out("evaluare.out");
    in>>s;
    out<<expresie();
}