Bit string

input/code.cpp: In function 'int main()':
input/code.cpp:12:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<s.size(); i++){
                  ~^~~~~~~~~

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ifstream fin("AAtest.in.txt");
string s;
ll mit,pa[2],pal,su;

int main(){
    ios::sync_with_stdio(0);
    getline(cin,s);
    pal=1;
    for(int i=0; i<s.size(); i++){

        if(s[i]=='1'){//cout<<pal<<" "<<mit<<" "<<pa[(mit+1)%2]<<" "<<"\n";
            su+=pal*pa[(mit+1)%2];
            su+=((pal-1)*(pal-2))/2+pal-1;
            mit++;
            pa[mit%2]+=pal;
            pal=0;
        }
        pal++;
    }
    su+=pal*pa[(mit+1)%2];
    su+=((pal-1)*(pal-2))/2+pal-1;
    cout<<su<<"\n";
}

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