Cod sursa(job #1189052)
Utilizator | Data | 21 mai 2014 10:47:35 | |
---|---|---|---|
Problema | Evaluarea unei expresii | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 1.33 kb |
#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("evaluare.in");
ofstream fout("evaluare.out");
char s[100020];
char *p=s;
int Term();
int Fact();
int Eval()
{
int r=Term();
while(*p=='+'||*p=='-')
{
if(*p=='+')
{
p++;
r+=Term();
}
else
{
p++;
r-=Term();
}
}
return r;
}
int Term()
{
int r=Fact();
while(*p=='*'||*p=='/')
{
if(*p=='*')
{
p++;
r*=Fact();
}
else
{
p++;
r/=Fact();
}
}
return r;
}
int Fact()
{
int r=0;
if(*p=='(')
{
++p;
r=Eval();
++p;
}
else
{
for(;*p>='0'&&*p<='9';p++)
{
r=r*10+*p-'0';
}
}
return r;
}
int main()
{
fin>>s;
fout<<Eval()<<'\n';
fin.close();
fout.close();
return 0;
}