Cod sursa(job #1267257)
Utilizator | Delia Draghici delia_99 | Data | 19 noiembrie 2014 18:15:11 |
---|---|---|---|
Problema | Evaluarea unei expresii | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 1.12 kb |
#include <cstdio>
using namespace std;
char s[100005],*p;
int n;
int eval();
int termen();
int factor();
int main()
{
freopen("evaluare.in","r",stdin);
freopen("evaluare.out","w",stdout);
gets(s);
p=s;
n=eval();
printf("%d\n",n);
return 0;
}
int eval()
{
int r;
r=termen();
while(*p=='+' || *p=='-')
{
if(*p=='+')
{
++p;
r+=termen();
}
if(*p=='-')
{
++p;
r-=termen();
}
}
return r;
}
int termen()
{
int r;
r=factor();
while(*p=='*' || *p=='/')
{
if(*p=='*')
{
++p;
r*=factor();
}
if(*p=='/')
{
++p;
r/=factor();
}
}
return r;
}
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;
}