Cod sursa(job #1410277)

Utilizator rzvrzvNicolescu Razvan rzvrzv Data 30 martie 2015 23:06:13
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.19 kb
#include<cstdio>
#include<cstring>
#include<cctype>

using namespace std;

char s[100002];
int i;

int termen();
int factor();
int eval();

int eval()
{
    int ans;
    ans=termen();
    for(;s[i]=='+'||s[i]=='-';)
    {
        if(s[i]=='+')
        {
            i++;
            ans+=termen();
        }
        else if(s[i]=='-')
        {
            i++;
            ans-=termen();
        }
    }
    return ans;
}

int termen()
{
    int ans;
    ans=factor();
    for(;s[i]=='*'||s[i]=='/';)
    {
        if(s[i]=='*')
        {
            i++;
            ans*=factor();
        }
        else if(s[i]=='/')
        {
            i++;
            ans/=factor();
        }
    }
    return ans;
}

int factor()
{
    int ans=0;
    if(s[i]=='(')
    {
        i++;
        ans=eval();
        i++;
        return ans;
    }
    else
    {
        while(isdigit(s[i]))
        {
            ans*=10;
            ans+=s[i]-48;
            i++;
        }
        return ans;
    }
}

int main()
{
    freopen("evaluare.in","r",stdin);
    freopen("evaluare.out","w",stdout);
    gets(s+1);
    i=1;
    printf("%d\n",eval());
}