压位暴力可过，甚至最优解第二

代码：

#include <stdio.h>
#include <string.h>

unsigned long long q[2048];

char op, bL, bR;
int L, R;

void range_set_0(int L, int R) {
	if (L > R) return;
	int qL = L >> 6, qR = R >> 6;
	if (qL == qR) {
		for (int i = L & 63; i <= R & 63; ++i) q[qL] &= ~(1ull << i);
		return;
	}
	memset(q + qL + 1, 0x00, sizeof(unsigned long long) * (qR - qL - 1));
	for (int i = L & 63; i < 64; ++i) q[qL] &= ~(1ull << i);
	for (int i = R & 63; i >= 0; --i) q[qR] &= ~(1ull << i);
}

void range_set_1(int L, int R) {
	if (L > R) return;
	int qL = L >> 6, qR = R >> 6;
	if (qL == qR) {
		for (int i = L & 63; i <= R & 63; ++i) q[qL] |= 1ull << i;
		return;
	}
	memset(q + qL + 1, 0xff, sizeof(unsigned long long) * (qR - qL - 1));
	for (int i = L & 63; i < 64; ++i) q[qL] |= 1ull << i;
	for (int i = R & 63; i >= 0; --i) q[qR] |= 1ull << i;
}

void range_rev(int L, int R) {
	if (L > R) return;
	int qL = L >> 6, qR = R >> 6;
	if (qL == qR) {
		for (int i = L & 63; i <= R & 63; ++i) q[qL] ^= 1ull << i;
		return;
	}
	for (int i = qL + 1; i < qR; ++i) q[i] = ~q[i];
	for (int i = L & 63; i < 64; ++i) q[qL] ^= 1ull << i;
	for (int i = R & 63; i >= 0; --i) q[qR] ^= 1ull << i;
}

int main() {
	while (~scanf(" %c %c%d,%d%c", &op, &bL, &L, &R, &bR)) {
		L = (L << 1) + (bL == '(');
		R = (R << 1) - (bR == ')');
		if (L <= R)
			switch (op) {
				case 'U': range_set_1(L, R); break;
				case 'D': range_set_0(L, R); break;
				case 'C': range_rev(L, R); // Fallthrough
				case 'I': range_set_0(0, L - 1); range_set_0(R + 1, 131070); break;
				case 'S': range_rev(L, R); break;
			}
		else {
			switch (op) {
				case 'C':
				case 'I': range_set_0(0, 131070); break;
			}
		}
	}
	bool found = false;
	for (int i = 0, now_l = -1; i < 131072; ++i) {
		if ((q[i >> 6] >> (i & 63)) & 1) {
			if (now_l == -1) now_l = i;
		} else if (now_l != -1) {
			found = true;
			printf("%c%d,%d%c ", now_l & 1 ? '(' : '[', now_l >> 1, i >> 1, i & 1 ? ']' : ')');
			now_l = -1;
		}
	}
	if (!found) printf("empty set");
	return 0;
}