Cod sursa(job #1943586)

Utilizator SkiryFarauanu Ionut Skiry Data 28 martie 2017 18:08:52
Problema Evaluarea unei expresii Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 1.04 kb
#include <fstream>

using namespace std;
ifstream f("evaluare.in");
ofstream g("evaluare.out");
char s[100001];
int i,r,n;
int eval();
int factor();
int termen();
int main()
{
    f.getline(s,100001);
    n=eval();
    g<<n;
    return 0;
}
int factor()
{
    int r=0;
    if(s[i]=='(')
    {
        ++i;
        r=eval();
        ++i;
    }
    else
    {
        while(s[i]>='0'&&s[i]<='9')
    {
        r*=10;
        r+=s[i]-'0';
        ++i;
    }
    }
    return r;
}
int termen()
{
    int r;
    r=factor();
    while(s[i]=='*'||s[i]=='/')
    {if(s[i]=='*')
    {
        ++i;
        r*=factor();
        break;
    }
    if(s[i]=='/')
    {
        ++i;
        r/=factor();
        break;
    }}
    return r;
}
int eval()
{
    int r;
    r=termen();
    while(s[i]=='+'||s[i]=='-')
    switch(s[i])
    {
        case '+':{
        ++i;
        r+=termen();
        break;
    }
    case '-':
    {
        ++i;
        r-=termen();
        break;
    }}
    return r;
}