old_contents: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  
  import numpy as np
  
  """Find a peak in 1D array.
  
  Support a is an array of length n.
  If a is an array of length 1, a[0] is a peak.
  In general, a[k] is a peak iff a[k] >= a[k - 1] and a[k] >= a[k + 1].
  If a[0] >= a[1], then a[0] is a peak.
  If a[n - 1] >= a[n - 2], then a[n - 1] is a peak.  
  """
  
  def find_peak_naive(arr):
      """Find peak by naive iteration.
  
      Time complexity: O(n).
      """
      for i in range(len(arr)):
          if i == 0:
              if arr[i] >= arr[i + 1]:
                  return arr[i]
          elif i == (len(arr) - 1):
              if arr[i] >= arr[i - 1]:
                  return arr[i]
          else:
              if arr[i] >= arr[i - 1] and arr[i] >= arr[i + 1]:
                  return arr[i]
  
  
  def find_peak(arr):
      """Find peak by divide-end-conquer algorithm.
  
      Time complexity: O(logn).
      """
      if len(arr) == 1:
          return arr[0]
      else:
          mid = len(arr) // 2
          if arr[mid] <= arr[mid - 1]:
              return find_peak(arr[:mid-1])
          elif arr[mid] <= arr[mid + 1]:
              return find_peak(arr[mid+1:])
          else:
              return arr[mid]
  
  
  def main():
      import time
  
      # Array of length 5 with peak 4.
      arr = [0, 1, 4, 3, 2]
      
      time_start = time.time()
      peak = find_peak_naive(arr)
      time_run = time.time() - time_start
      print('Peak: {}'.format(peak))
      print('Time for find_peak_naive(): {}'.format(time_run))
  
      time_start = time.time()
      peak = find_peak(arr)
      time_run = time.time() - time_start
      print('Peak: {}'.format(peak))
      print('Time for find_peak_naive(): {}'.format(time_run))
  
      # Array of long length.
      arr = np.random.permutation(10000000)
  
      time_start = time.time()
      peak = find_peak_naive(arr)
      time_run = time.time() - time_start
      print('Peak: {}'.format(peak))
      print('Time for find_peak_naive(): {}'.format(time_run))
  
      time_start = time.time()
      peak = find_peak(arr)
      time_run = time.time() - time_start
      print('Peak: {}'.format(peak))
      print('Time for find_peak_naive(): {}'.format(time_run))
  
  
  if __name__ == '__main__':
      main()
  
new_contents: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  
  import numpy as np
  
  """
  Find a peak in 1D array.
  
  Support a is an array of length n.
  If a is an array of length 1, a[0] is a peak.
  In general, a[k] is a peak iff a[k] >= a[k - 1] and a[k] >= a[k + 1].
  If a[0] >= a[1], then a[0] is a peak.
  If a[n - 1] >= a[n - 2], then a[n - 1] is a peak.  
  """
  
  def find_peak_naive(arr):
      """Find peak by naive iteration.
  
      Time complexity: O(n).
      """
      for i in range(len(arr)):
          if i == 0:
              if arr[i] >= arr[i + 1]:
                  return arr[i]
          elif i == (len(arr) - 1):
              if arr[i] >= arr[i - 1]:
                  return arr[i]
          else:
              if arr[i] >= arr[i - 1] and arr[i] >= arr[i + 1]:
                  return arr[i]
  
  
  def find_peak(arr):
      """Find peak by divide-end-conquer algorithm.
  
      Time complexity: O(logn).
      """
      if len(arr) == 1:
          return arr[0]
      else:
          mid = len(arr) // 2
          if arr[mid] <= arr[mid - 1]:
              return find_peak(arr[:mid-1])
          elif arr[mid] <= arr[mid + 1]:
              return find_peak(arr[mid+1:])
          else:
              return arr[mid]
  
  
  def main():
      import time
  
      # Array of length 5 with peak 4.
      arr = [0, 1, 4, 3, 2]
      
      time_start = time.time()
      peak = find_peak_naive(arr)
      time_run = time.time() - time_start
      print('Peak: {}'.format(peak))
      print('Time for find_peak_naive(): {}'.format(time_run))
  
      time_start = time.time()
      peak = find_peak(arr)
      time_run = time.time() - time_start
      print('Peak: {}'.format(peak))
      print('Time for find_peak_naive(): {}'.format(time_run))
  
      # Array of long length.
      arr = np.random.permutation(10000000)
  
      time_start = time.time()
      peak = find_peak_naive(arr)
      time_run = time.time() - time_start
      print('Peak: {}'.format(peak))
      print('Time for find_peak_naive(): {}'.format(time_run))
  
      time_start = time.time()
      peak = find_peak(arr)
      time_run = time.time() - time_start
      print('Peak: {}'.format(peak))
      print('Time for find_peak_naive(): {}'.format(time_run))
  
  
  if __name__ == '__main__':
      main()
  
subject: Revise script docstring