Cod sursa(job #1570471)

Utilizator stanciuandreiStanciulescu Andrei stanciuandrei Data 16 ianuarie 2016 16:06:51
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.14 kb
#include <iostream>
#include <fstream>
#define N 100000
using namespace std;
ifstream in("evaluare.in");
ofstream out("evaluare.out");
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]=='-')
    {
        semn=-semn;
        p++;
    }
    if(s[p]=='(')
    {
        p++;
        val=expresie();
        p++;
        return semn*val;
    }
    while(s[p]>='0'&&s[p]<='9'){
        val=val*10+(s[p]-'0');
        p++;
    }
    return semn*val;
}
int main()
{
    in>>s;
    out<<expresie();
    return 0;
}