Cod sursa(job #3153119)

Utilizator Federica361Martinut Federica Federica361 Data 28 septembrie 2023 11:56:02
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.97 kb
#include <bits/stdc++.h>

using namespace std;

const long MAX = 100010;
char S[100010], *p=S;

long termen();
long factor();

long eval()
{
	long r = termen();
	while ( *p=='+' || *p=='-' )
    {
		switch ( *p )
		{
			case '+':
				++p;
				r += termen();
				break;
			case '-':
				++p;
				r -= termen();
				break;
		}
	}
	return r;
}

long termen()
{
	long r = factor();
	while ( *p=='*' || *p=='/' )
    {
		switch ( *p )
		{
			case '*' :
				++p;
				r *= factor();
				break;
			case '/':
				++p;
				r /= factor();
				break;
		}
	}
	return r;
}

long factor()
{
    long r=0;
    if ( *p == '(' )
    {
        ++p;
		r = eval();
		++p;
    } else
    {
        while ( *p>='0' && *p<='9' )
        {
            r = r*10 + *p - '0';
			++p;
		}
    }
    return r;
}

int main()
{
    fgets(S, MAX, fopen("evaluare.in", "r"));
    fprintf(fopen("evaluare.out", "w"), "%ld\n", eval());
    return 0;
}