Finding the largest subarray with equal number of 0's and 1's

Question

So, I have an array containing only 0\'s and 1\'s. I have to find out the largest subarray containing equal number of 0\'s and 1\'s. One can be a naive approach have complex

Answer 1

int maxLen(int nums[], int n)
{   
    unordered_map m;
    m[0] = -1;
    int ans = 0, cur = 0;
    for (int i = 0; i < n; ++i) {
        cur += nums[i] ? 1 : -1;
        if (m.count(cur))
            ans = max(ans, i - m[cur]);
        else
            m[cur] = i;
    }
    return ans;
}