Cod sursa(job #1277159)

Utilizator DiClauDan Claudiu DiClau Data 27 noiembrie 2014 11:33:20
Problema Evaluarea unei expresii Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.3 kb
#include<stdio.h>
using namespace std;

const int N = 100002;
int p = 1;
char s[N];

int expresie();
int termen();
int factor();

int expresie()
{
    int sum = termen();
    while (s[p] == '+' || s[p] == '-')
    {
        if (s[p] == '+')
        {
            p++;
            sum += termen();
        }
        if (s[p] == '-')
        {
            p++;
            sum -= termen();
        }
        p++;
    }
    return sum;
}

int termen()
{
    int prod = factor();
    while (s[p] == '*' || s[p] == '/')
    {
        if (s[p] == '*')
        {
            p++;
            prod *= factor();
        }
        if (s[p] == '/')
        {
            p++;
            prod /= factor();
        }
    }
    return prod;
}

int factor()
{
    int semn = 1, val = 0;
    if (s[p] == '-')
    {
        semn = -semn;
        p++;
    }
    if (s[p] == '(')
    {
        p++;
        val = expresie();
        return semn * val;
    }
    while (s[p] >= '0' && s[p] <= '9')
        val = val * 10 + s[p++] - '0';
    return semn * val;
}
int main ()
{
    FILE *in, *out;
    in = fopen ("evaluare.in", "r");
    out = fopen ("evaluare.out", "w");
    char x = '0';
    x = fgetc(in);
    int c = 0;
    while (x != '\n')
    {
        s[++c] = x;
        x = fgetc(in);
    }
    fprintf(out, "%d", expresie());
    return 0;
}