Cod sursă (job #97993)

#include <stdio.h>
#include <ctype.h>
#include <vector>
#define N_MAX 100000

using namespace std;

FILE *fin, *fout;
char str[N_MAX + 2]; // Inca 2 elemente pentru '\n' si '\0'
int size, sp;

/*
	Gramatica expresiei:
	E = N [L]*
	L = '(' [E ',']* ')'
*/

int E();
int N();
vector<int> L();

int E()
{
	int ans = N();
	while (str[sp] == '(') {
		vector<int> v = L();
		ans = v[(ans - 1) % v.size()];
	}
	return ans;
}

vector<int> L()
{
	vector<int> ans;
	sp++; // Sarim peste '('
	while (str[sp - 1] != ')') {
		ans.push_back(E());
		sp++;
	}
	return ans;
}

int N()
{
	int ans = 0;
	while (isdigit(str[sp])) {
		ans = ans * 10 + str[sp++] - '0';
	}
	return ans;
}

int main()
{
	fin = fopen("bizar.in", "r");
	fout = fopen("bizar.out", "w");

	// Citire
	while ((str[size++] = fgetc(fin)) != '\n') {
		if (str[size - 1] == ' ') {
			size--;
		}
	}

	fprintf(fout, "%d", E());

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