Cod sursa(job #2271304)

Utilizator marian013Giugioiu Marian Constantin marian013 Data 28 octombrie 2018 13:13:21
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.17 kb
#include <fstream>
using namespace std;
char s[100010],*p=s;
long termen();
long factor();
long eval(){
    long r=termen();
    while(*p=='+'||*p=='-')
         switch(*p){
         case '+':
            {
                ++p;
                r+=termen();
                break;
            }
         case '-':
            {
                ++p;
                r-=termen();
                break;
            }
         }
    return r;
}
long termen(){
    long r=factor();
    while(*p=='*'||*p=='/')
         switch(*p){
         case '*':
            {
                ++p;
                r*=factor();
                break;
            }
         case '/':
            {
                ++p;
                r/=factor();
                break;
            }
         }
    return r;
}
long factor(){
    long r=0;
    if(*p=='(')
    {
        ++p;
        r=eval();
        ++p;
    }
    else
    {
        while(*p>='0'&&*p<='9')
        {
            r=r*10+*p-'0';
            ++p;
        }
    }
    return r;
}
int main()
{
    ifstream f("evaluare.in");
    ofstream g("evaluare.out");
    f>>s;
    g<<eval();
}