Cod sursa(job #3030247)

Utilizator ValuMunteanu Valentin Valu Data 17 martie 2023 16:13:34
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.15 kb
#include <fstream>
using namespace std;

ifstream f("evaluare.in");
ofstream g("evaluare.out");

long long expresie();
long long termen();
long long factor();
long long constanta();
int i;
char s[100001];

  long long expresie()
  {
    long long r=termen();

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

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

     r*=factor();}
    if(s[i]=='/')
    {
     i++;
     r/=factor();


    }
  }
    return r;
  }

  long long factor()
  {
    long long  r;
    if(s[i]=='(')
    {
     i++;
     r=expresie();
     i++;
    }
    else
    {
     r=constanta();

    }
    return r;

  }

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

  int main()
  {
    f>>s;
    i=0;
    g<<expresie();
    return 0;
  }