Bittijono

input/code.cpp: In function 'int main()':
input/code.cpp:18:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<s.size(); i++) {
               ~^~~~~~~~~

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define ld long double
#define N (1<<18)
#define M 1000000007

using namespace std;

ll d[505050][2], ans;
string s;

int main() {
	cin.tie(0);
	cout.tie(0);
	ios_base::sync_with_stdio(0);
	cin >> s;
	for(int i=0; i<s.size(); i++) {
		if(s[i] == '0') {
			if(i) {
			d[i][0] += d[i-1][0];
			d[i][1] += d[i-1][1];
			}
			d[i][0]++;
			ans += d[i][0];
		} else { // 1
			if(i) {
			d[i][0] += d[i-1][1];
			d[i][1] += d[i-1][0];
			}
			d[i][1]++;
			ans += d[i][0];
		}
	}
	cout << ans;
}

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: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 2

Verdict: ACCEPTED

Test 12

Group: 2

Verdict: ACCEPTED

Test 13

Group: 2

Verdict: ACCEPTED

Test 14

Group: 2

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED

Test 16

Group: 3

Verdict: ACCEPTED

Test 17

Group: 3

Verdict: ACCEPTED

Test 18

Group: 3

Verdict: ACCEPTED

Test 19

Group: 3

Verdict: ACCEPTED

Test 20

Group: 3

Verdict: ACCEPTED

Test 21

Group: 3

Verdict: ACCEPTED