m = [1,1,1,0,_,0,0,1,0,0,1,1] -> 2

[0,0,0] -> -1 // inf

int max_len = 0;
int cur_len = 0;
int ind_max = 0;

for(int i = 0; i m.size(); ++i){
    if(m[i] == 1){
        if(cur_len > max_len){
            max_len = cur_len;
            ind_max = i;
            cur_len = 0;
        }
        else{
            ++cur_len;
        }
    }
}
if(cur_len > max_len) {
    max_len = cur_len;
    ind_max = i;
    cur_len = 0;
}

if(cur_len == m.size()){
    return -1;
}

int max_left = 0;
int max_right = 0;
while(max_left < m.size() && m[max_left] == 0) ++max_left;
while(max_right < m.size() && m[m.size() - 1 - max_right] == 0) ++max_right;

return max({(max_len + 1) / 2, max_left, max_right});



-----------------------------------------

a = [-2,-2,-2,-2,-1,0,2,3] сорт
b = [-4,-3,-1,0,0,2,2,2,2,2,2] сорт
x = 0

#{(i,j) | a[i] + b[j] == x}

long long answer = 0;

int i = 0;
int j = b.size() - 1;

while(i < a.size() && b >= 0){
    if(a[i] + b[j] == x){
        int count_in_a = 1;
        int count_int_b = 1;
        while(i + 1 < a.size() && a[i + 1] == a[i]){
            count_in_a++;
            ++i;
        }
        while(j - 1 >= 0 && b[j - 1] == b[j]){
            count_in_b++;
            --j;
        }

        answer += count_in_a * count_in_b;
        ++i;
        --j;
    }
    else if(a[i] + b[j] < x){
        ++i;
    }
    else{
        --j;
    }
}

return answer;