How to find largest alternating subsequence of 1s and 0s in a string

Find largest alternating 1s and 0s subsequence in a string containing only 1s and 0s.also find the starting index for the largest subsequence

Example for 1101011 rhe longest alternating subsequence length is 5 from index 1 to 5.

Tried doing it by comparing consecutive elements and if they are not equal checking current length with max size. Need help with code

int findSubArray(int arr[], int n) 
{
    int sum = 0;
    int maxsize = -1, startindex = 0;
    int endindex = 0;

    int j = 0;
    for (int i = 0; i < n - 1; i++) 
    {
        if (arr[i] != arr[i+1] && maxsize < i - j + 1) 
        {
            maxsize = i - j + 1;
            startindex = j;
        } else {
            j = i;
        }
    }

    endindex = startindex+maxsize-1;
    if (maxsize == -1)
        System.out.println("No such subarray");
    else
        System.out.println(startindex+" to "+endindex);

    return maxsize;
}