Cod sursa(job #795665)

Utilizator bogfodorBogdan Fodor bogfodor Data 9 octombrie 2012 11:45:36
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.11 kb
#include <cstdio>
#include <cstring>
#include <cctype>
#define Lmax 100001
using namespace std;

FILE *fin=freopen("evaluare.in","r",stdin);
FILE *fout=freopen("evaluare.out","w",stdout);

char s[Lmax];
int i=0;

int num();
int mult();

int solve()
{
    long t=mult();
    while(s[i]=='+' || s[i]=='-')
    {
        if(s[i]=='+')
        {
            i++;
            t+=mult();
        }
        else
        {
            i++;
            t-=mult();
        }
    }
    return t;
    }

int mult()
{
    long t=num();
    while(s[i]=='*' || s[i]=='/')
    {
        if(s[i]=='*')
        {
            i++;
            t*=num();
        }
        else
        {
            i++;
            t/=num();
        }
    }
    return t;
}

int num()
{
    int t=0;
    if(s[i]=='(')
    {
        i++;
        t=solve();
        i++;
    }
    else
        while(isdigit(s[i]))
        {
            t=t*10+s[i++]-'0';
        }
    return t;
}

void citire()
{
    fgets(s,Lmax,stdin);
}

int main()
{
    citire();
    printf("%d\n",solve());
    return 0;
}