Find subarray length with target elements and order doesn't matter, target can have duplicates

FindSmallestSubstringContainingAllKeys.cs

/*
9:00pm
brute force

target [1,2,2,3]
arr[1,1,1,2,2,2,3,1,2,3]
find subarray length with all target elements and order doesn't matter, target can have duplicates, 
3,2,2,1
go through -> start position
1 1
2 2
3 1
Find small smll
*/
public static int FindShortestSubArrayLengthContainingAllKeys(int[] numbers, int[] target)
{
  if(numbers == null || target == null || numbers.Length < target.Length)
    return -1; 
  
  var sLength = numbers.Length; 
  var tLength = target.Length; 
  
  var dict = new Dictionary<int, int>(); 
  foreach(var item in target)
  {
    if(dict.ContainsKey(item))
      dict[item]++; 
    else
      dict.Add(item, 1); 
  }
  
  int minLength = Int.MaxValue; 
  int numbersFound = 0; 
  
  int start = 0; 
  for(int index = 0; index < numbers; index++)
  {
    var current = numbers[index]; 
    
    if(dict.ContainsKey(current))
      continue; 
  
    if(dict[current] > 0)
    {      
      numbersFound++; 
    }
    
    dict[current]--;
    
    // slide left pointer 
    while(numbersFound == tLength)
    {
      // record the length
      var currentLength = index - start + 1; 
      minLength = currentLength < minLength ? currentLength : minLength;       
      
      // skip left if it is ok 
      var leftValue = numbers[start];
      
      if(dict.ContainsKey(leftValue)) 
      {
        if(dict[leftValue] >=0)                  
          numbersFound--;         
        
        dict[leftValue]++;   
      }
      
      start++; 
    }       
  }
  
  // return minimum length
  return minLength == int.MaxValue? -1 : minLength; 
}