LeetCode - Contiguous Array - 30Days Challenge

Given a binary array, find the maximum length of a contiguous subarray with equal number of 0 and 1.

Example 1:

Input: [0,1] Output: 2 Explanation: [0, 1] is the longest contiguous subarray with equal number of 0 and 1.

Example 2:

Input: [0,1,0] Output: 2 Explanation: [0, 1] (or [1, 0]) is a longest contiguous subarray with equal number of 0 and 1.

Note: The length of the given binary array will not exceed 50,000.

Code


 class Solution {
    public int findMaxLength(int[] nums) {
        int[] arr = new int[2 * nums.length + 1];
        Arrays.fill(arr, -2);
        arr[nums.length] = -1;
        int maxlen = 0, count = 0;
        for (int i = 0; i < nums.length; i++) {
            count = count + (nums[i] == 0 ? -1 : 1);
            if (arr[count + nums.length] >= -1) {
                maxlen = Math.max(maxlen, i - arr[count + nums.length]);
            } else {
                arr[count + nums.length] = i;
            }

        }
        return maxlen;
    }
}