Cod sursa(job #1088683)
Utilizator | Data | 20 ianuarie 2014 19:01:25 | |
---|---|---|---|
Problema | Evaluarea unei expresii | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 1.06 kb |
#include <fstream>
#include <cstring>
using namespace std;
ifstream f("evaluare.in");
ofstream g("evaluare.out");
char s[1000],*p;
int n;
int eval();
int termen();
int factor();
int main()
{
f.get(s,100000);
p=s;
n=eval();
g<<n;
}
int eval()
{
int r;
r=termen();
while(*p=='+'||*p=='-')
{
if(*p='+')
{
++p;
r+=termen();
}
if(*p='-')
{
++p;
r-=termen();
}
}
}
int termen()
{
int r;
r=factor();
while(*p=='*'||*p=='/')
{
if(*p='*')
{
++p;
r*=factor();
}
if(*p='/')
{
++p;
r/=factor();
}
}
}
int factor()
{
int r;
r=0;
if(*p='(')
{
++p;
r=eval();
++p;
}
else
{
while('0'<=*p && *p<='9')
{
r*=10;
r+=(int)*p-'0';
++p;
}
}
return r;
}