Cod sursa(job #2379596)

Utilizator sansRotaru Razvan Andrei sans Data 13 martie 2019 20:46:02
Problema Evaluarea unei expresii Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.95 kb
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define MAX 100010
char s[MAX], *p=s;
ll expr();
ll subexpr();
ll eval() {
	ll r = expr();
	while ( *p=='+' || *p=='-' ) {
		switch ( *p ) {
			case '+':
				++p;
				r += expr();
				break;
			case '-':
				++p;
				r -= expr();
				break;
		}
	}
	return r;
}

ll expr(){
    ll r = subexpr();
	while ( *p=='*' || *p=='/' ) {
		switch ( *p ) {
			case '*' :
				++p;
				r *= subexpr();
				break;
			case '/':
				++p;
				r /= subexpr();
				break;
		}
	}
	return r;

}
ll subexpr(){
    ll r = 0;
    if ( *p == '(' ) {
        ++p;
		r = eval();
		++p;
    }
    else {
        while ( *p>='0' && *p<='9' )  {
            r = r*10 + *p - '0';
			++p;
		}
    }
    return r;
}
int main(){
    freopen("evaluare.in", "r", stdin);
    freopen("evaluare.out", "w", stdout);
    fgets(s, MAX, stdin);
    printf("%lld", eval());
    return 0;
}