new_contents: """Leetcode 398. Random Pick Index
  Medium
  
  URL: https://leetcode.com/problems/random-pick-index/
  
  Given an array of integers with possible duplicates, randomly output the index
  of a given target number. You can assume that the given target number must
  exist in the array.
  
  Note:
  The array size can be very large. Solution that uses too much extra space will
  not pass the judge.
  
  Example:
  int[] nums = new int[] {1,2,3,3,3};
  Solution solution = new Solution(nums);
  // pick(3) should return either index 2, 3, or 4 randomly. Each index should have equal probability of returning.
  solution.pick(3);
  // pick(1) should return 0. Since in the array only nums[0] is equal to 1.
  solution.pick(1);
  """
  
  class Solution(object):
      def __init__(self, nums):
          """
          :type nums: List[int]
          """
          pass
  
      def pick(self, target):
          """
          :type target: int
          :rtype: int
          """
          pass
  
  
  def main():
      pass
  
  
  if __name__ == '__main__':
      main()
  
subject: Add lc0398_random_pick_index.py