Cod sursa(job #1571747)

Utilizator penetavyPene Cosmin-Octavian penetavy Data 18 ianuarie 2016 14:34:32
Problema Evaluarea unei expresii Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.19 kb
#include <stdio.h>

using namespace std;

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

char s[100001];
int p;

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

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

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

int factor(){
    int semn = 1, val = 0;
    while(s[p] == '-'){
        semn = -semn;
        p++;
    }
    if(s[p] == '('){
        p++;
        val = expresie();
        p++;
        return semn * val;
    }
    while(s[p] >= '0' && s[p] <= '9'){
        val = val * 10 + (s[p] - '0');
        p++;
//        return semn * val;
    }
    return semn * val;
}

int main(){

    fscanf(fin, "%s", s);
    fprintf(fout, "%d", expresie());

    return 0;
}