Cod sursa(job #2915565)

Utilizator alexandru_ioan.06Alexandru Ioan alexandru_ioan.06 Data 23 iulie 2022 13:41:25
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.08 kb
#include <fstream>
using namespace std;
ifstream cin ("evaluare.in");
ofstream cout ("evaluare.out");
int i;
char s[100001];
int expresie();
int termen();
int factor();
int constanta();
int main()
{
    cin>>s;
    i=0;
    cout<<expresie();
}
int expresie()
{
    int r=termen();
    while(s[i]=='+' || s[i]=='-'){
        if(s[i]=='+')
        {
            ++i;
            r+=termen();
        }
        else
        {
            ++i;
            r-=termen();
        }
    }
    return r;
}
int termen()
{
    int r=factor();
    while(s[i]=='/' || s[i]=='*')
    {
        if(s[i]=='/')
        {
            i++;
            r/=factor();
        }
        else
        {
            i++;
            r*=factor();
        }
    }
    return r;
}
int factor()
{
    int r;
    if(s[i]=='(')
    {
        ++i;
        r=expresie();
        ++i;
    }
    else r=constanta();
    return r;
}
int constanta()
{
    int r=0;
    while(s[i]>='0' && s[i]<='9')
    {
        r=r*10+s[i]-'0';
        ++i;
    }
    return r;
}