Cod sursa(job #2427180)
| Utilizator | Data | 31 mai 2019 08:07:08 | |
|---|---|---|---|
| Problema | Evaluarea unei expresii | Scor | 100 |
| Compilator | cpp-64 | Status | done |
| Runda | Arhiva educationala | Marime | 1.17 kb |
#include <fstream>
using namespace std;
ifstream f("evaluare.in");
ofstream g("evaluare.out");
int i;
char s[100100];
int eval();
int termen();
int factor();
int eval()
{
int r = termen();
while(s[i] == '+' || s[i] == '-')
{ if(s[i] == '+')
{ i++;
r = r + termen();
}
else
{ i++;
r = r - termen();
}
}
return r;
}
int termen()
{
int r = factor();
while(s[i] == '*' || s[i] == '/')
{ if(s[i] == '*')
{ i++;
r = r * factor();
}
else
{ i++;
r = r / factor();
}
}
return r;
}
int factor()
{
int r = 0;
if(s[i] == '(')
{ i++;
r = eval();
i++;
}
else
{ while(s[i] >= '0' && s[i] <= '9')
{ r = r * 10 + s[i] - '0';
i++;
}
}
return r;
}
int main()
{
f >> s;
g << eval() << '\n';
return 0;
}
