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.
Solution: (Hashing)
class Solution
{
public:
int findMaxLength(vector<int> &nums)
{
int count = 0;
int res = 0;
unordered_map<int, int> m;
m[0] = -1;
for (int i = 0; i < nums.size(); i++)
{
if (nums[i] == 1)
{
count--;
}
else
{
count++;
}
if (m.find(count) != m.end())
{
int dif = i - m[count];
res = max(res, dif);
}
else
{
m[count] = i;
}
}
return res;
}
};