Cod sursa(job #710681)

Utilizator hunter_ionutzzzFarcas Ionut hunter_ionutzzz Data 10 martie 2012 16:20:41
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.67 kb
#include<fstream>
using namespace std;
ifstream fin("evaluare.in");
ofstream fout("evaluare.out");
char s[100005];
int p=0,termen(),factor();
int expresie()
{int sum=termen();
	while(s[p]=='+' || s[p]=='-')
	{   ++p;
		if(s[p-1]=='+')
			sum+=termen();
		else 
			sum-=termen();
	}
	return sum;
}
int termen()
{int sum=factor();
	while(s[p]=='*' || s[p]=='/')
	{	p++;
		if(s[p-1]=='*')
			sum*=factor();
		else 
			sum/=factor();
	}
	return sum;
}
int factor()
{int val=0;
	if(s[p]=='(')
	{	++p;
		val=expresie();
		++p;
	}
	else 
		while (s[p]>='0' && s[p]<='9')
		{	val=val*10+(s[p]-'0');
			++p;
		}
	return val;
}
int main()
{   fin >> s;
    fout << expresie();
	return 0;
}