Cod sursa(job #2535372)

Utilizator MatteoalexandruMatteo Verzotti Matteoalexandru Data 31 ianuarie 2020 20:07:16
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.1 kb
#include <bits/stdc++.h>

using namespace std;

const int N = 1e5;

char s[5 + N];
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 val(0), semn(1);
    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');
    return semn * val;
}

int main() {
    freopen("evaluare.in", "r", stdin);
    freopen("evaluare.out", "w", stdout);
    fgets(s, 3 + N, stdin);
    printf("%d\n", expresie());
    return 0;
}