Given a binary array nums, return the maximum length of a contiguous subarray with an equal number of 0 and 1.
Example 1:
Input: nums = [0,1]
Output: 2
Explanation: [0, 1] is the longest contiguous subarray with an equal number of 0 and 1.
Example 2:
Input: nums = [0,1,0]
Output: 2
Explanation: [0, 1] (or [1, 0]) is a longest contiguous subarray with equal number of 0 and 1.
Constraints:
1 <= nums.length <= 105
nums[i] is either 0 or 1.
Solutions:
class Solution {
public int findMaxLength(int[] nums) {
for(int i=0;i<nums.length;i++)
{
if(nums[i]==0)
nums[i]=-1;
}
Map<Integer,Integer> map = new HashMap<>();
map.put(0,-1);
int sum=0, max=0;
for(int i=0;i<nums.length;i++)
{
sum+=nums[i];
if(map.containsKey(sum))
{
max=Math.max(max, i-map.get(sum));
}
else
{
map.put(sum,i);
}
}
return max;
}
}