Cod sursa(job #1814770)

Utilizator andrew_assassin789Andrei Manea andrew_assassin789 Data 24 noiembrie 2016 15:34:38
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.86 kb
#include <fstream>
#include <cstring>
using namespace std;
#define nmax 100010
char op[3][3] = { "+-", "*/", "^"};
char s[nmax], *p = s;
int eval( int a, int b, char o )
{
    if (o=='+') return a+b;
    if (o=='-') return a-b;
    if (o=='/') return a/b;
    if (o=='*') return a*b;
}
int expr(int ordin)
{
    int x,y;char o;
    if (ordin==2)
    {
        if (*p=='(')
            ++p,x=expr(0),++p;
        else
            for (x=0; '0'<=*p && *p<='9'; p++)
                x=10*x+*p-'0';
    }
    else
    {
        x=expr(ordin+1);
        for ( ; strchr(op[ordin],*p) && *p!=0; x=y )
            y=eval( x, expr(ordin+1), *p++ );
    }
    return x;
}
int main()
{
    ifstream fin("evaluare.in");
    ofstream fout("evaluare.out");
    fin.get(s,nmax);
    fin.close();
    fout<<expr(0)<<'\n';
    fout.close();
    return 0;
}