## Algorithm

Problem Name: 1224. Maximum Equal Frequency

Given an array `nums` of positive integers, return the longest possible length of an array prefix of `nums`, such that it is possible to remove exactly one element from this prefix so that every number that has appeared in it will have the same number of occurrences.

If after removing one element there are no remaining elements, it's still considered that every appeared number has the same number of ocurrences (0).

Example 1:

```Input: nums = [2,2,1,1,5,3,3,5]
Output: 7
Explanation: For the subarray [2,2,1,1,5,3,3] of length 7, if we remove nums[4] = 5, we will get [2,2,1,1,3,3], so that each number will appear exactly twice.
```

Example 2:

```Input: nums = [1,1,1,2,2,2,3,3,3,4,4,4,5]
Output: 13
```

Constraints:

• `2 <= nums.length <= 105`
• `1 <= nums[i] <= 105`

## Code Examples

### #1 Code Example with Javascript Programming

```Code - Javascript Programming```

``````
const maxEqualFreq = function (nums) {
const freqCnt = {}, cnt = {}, { max } = Math

let res = 0, maxF = 0, i = 0
for(const e of nums) {
if(cnt[e] == null) cnt[e] = 0
cnt[e]++

const f = cnt[e]

if(freqCnt[f - 1] == null) freqCnt[f - 1] = 0
if(freqCnt[f] == null) freqCnt[f] = 0

if(freqCnt[f - 1] > 0) freqCnt[f - 1]--
freqCnt[f]++

maxF = max(maxF, f)

if(
maxF === 1 ||
maxF * freqCnt[maxF] === i ||
(maxF - 1) * (freqCnt[maxF - 1] + 1) === i
) {
res = i + 1
}

i++
}

return res
}
``````
Copy The Code &

Input

cmd
nums = [2,2,1,1,5,3,3,5]

Output

cmd
7

### #2 Code Example with Python Programming

```Code - Python Programming```

``````
class Solution:
def maxEqualFreq(self, nums: List[int]) -> int:
def okay():
if len(dic) == 1 and (1 in dic or 1 in dic.values()):
return True
if len(dic) == 2:
c1, c2 = sorted(dic.keys())
if c2 - c1 == 1 and dic[c2] == 1 or (c1 == 1 and dic[1] == 1):
return True
cnt = collections.Counter(nums)
dic = collections.Counter(cnt.values())
l = len(nums)
for num in nums[::-1]:
if okay():
return l
dic[cnt[num]] -= 1
if not dic[cnt[num]]:
dic.pop(cnt[num])
cnt[num] -= 1
if cnt[num]:
dic[cnt[num]] += 1
l -= 1
if okay():
return l
``````
Copy The Code &

Input

cmd
nums = [2,2,1,1,5,3,3,5]

Output

cmd
7