Cod sursa(job #2520074)

Utilizator marinaoprOprea Marina marinaopr Data 8 ianuarie 2020 21:09:43
Problema Evaluarea unei expresii Scor 10
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.24 kb
#include <stdio.h>
#include <string.h>

using namespace std;

FILE *fin = fopen("evaluare.in", "r");
FILE *fout = fopen("evaluare.out", "w");

int n;
char sir[100005],*p;

int eval();
int termen();
int factor();

int main()
{
    fgets(sir, 100002, fin);
    n = strlen(sir)-1;

    p = sir;
    fprintf(fout, "%d", eval());

    fclose(fin);
    fclose(fout);
    return 0;
}

int factor()
{
    int r;

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

int termen()
{
    int ans = 1;

    ans = factor();
    while(*p == '*' or *p == '/')
        if(*p == '*')
        {
            ++p;
            ans *= factor();
        }
        else
        {
            ++p;
            ans /= factor();
        }

    return ans;
}

int eval()
{
    int ans = 0;

    ans = termen();
    while(*p == '+' or *p == '-')
        if(*p == '+')
        {
            ++p;
            ans += termen();
        }
        else
        {
            ++p;
            ans += termen();
        }

    return ans;
}