Bittijono

#include <cstdint>
#include <bits/stdc++.h>

bool evenBits(std::string const & input, uint64_t a, uint64_t b) {
	uint8_t ok = 1;
	for (uint64_t i = a; i < b; ++i) {
		if (input[i] == '1') {
			ok ^= 1;
		}
	}
	return ok == 1;
}

int main() {
	std::string input;
	std::cin >> input;

	uint64_t counter = 0;

	for (uint64_t i = 0; i < input.size(); ++i) {
		for (uint64_t j = input.size(); j > i; --j) {
//			std::cout << i << " " << j << " ";
			if (evenBits(input, i, j)) {
				++counter;
//				std::cout << "EVEN" << std::endl;
			} else {
//				std::cout << "ODD" << std::endl;
			}
		}
	}

	std::cout << counter << std::endl;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 1

Verdict: ACCEPTED

Test 7

Group: 1

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 9

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 10

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 11

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 12

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 13

Group: 2

Verdict: ACCEPTED

Test 14

Group: 2

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 16

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 17

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 18

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 19

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 20

Group: 3

Verdict: ACCEPTED

Test 21

Group: 3

Verdict: ACCEPTED