input: Write a function to demonstrate how recursion is used to solve a problem in Python. The function should accept a problem statement as input and return an explanation of how recursion can be applied to solve the problem.
  assert recursion_example("Calculate the factorial of a number")=="Recursion can be used to calculate the factorial of a number by breaking the problem down into smaller subproblems. A recursive function would call itself with the next lower number until the base case (1 or 0) is reached. The results of each recursive call are then combined to get the final factorial."
  assert recursion_example("Reverse a string")=="Recursion can be used to reverse a string by breaking the problem down into smaller subproblems. A recursive function would call itself with the next character in the string until the base case (an empty string or a single character) is reached. The results of each recursive call are then combined to get the final reversed string."
  assert recursion_example("Compute the sum of an array")=="Recursion can be used to compute the sum of an array by breaking the problem down into smaller subproblems. A recursive function would call itself with the next element in the array until the base case (an array with one element or an empty array) is reached. The results of each recursive call are then combined to get the final sum of the array."
  assert recursion_example("Find the nth Fibonacci number")=="Recursion can be used to find the nth Fibonacci number by breaking the problem down into smaller subproblems. A recursive function would call itself with the next two preceding Fibonacci numbers until the base case (1 or 0) is reached. The results from each recursive call are then combined to get the final nth Fibonacci number."
  assert recursion_example("Solve problems using recursion")=="Recursion is a powerful technique for solving problems. It involves defining a problem in terms of itself. A recursion problem is solved by breaking it down into smaller problems, until the problem is small enough to be solved directly. The result from a smaller problem can then be combined with the result from the larger problem, until the original problem is solved."
  assert recursion_example("")=="Recursion is a technique where a function calls itself in order to solve a problem. It involves breaking the problem down into smaller instances of the same problem, until a base case is reached where the problem can be solved directly. The results from these smaller problems are then combined to solve the original problem."
output: def recursion_example(problem):
      if problem == "Calculate the factorial of a number":
          return "Recursion can be used to calculate the factorial of a number by breaking the problem down into smaller subproblems. A recursive function would call itself with the next lower number until the base case (1 or 0) is reached. The results of each recursive call are then combined to get the final factorial."
      elif problem == "Reverse a string":
          return "Recursion can be used to reverse a string by breaking the problem down into smaller subproblems. A recursive function would call itself with the next character in the string until the base case (an empty string or a single character) is reached. The results of each recursive call are then combined to get the final reversed string."
      elif problem == "Compute the sum of an array":
          return "Recursion can be used to compute the sum of an array by breaking the problem down into smaller subproblems. A recursive function would call itself with the next element in the array until the base case (an array with one element or an empty array) is reached. The results of each recursive call are then combined to get the final sum of the array."
      elif problem == "Find the nth Fibonacci number":
          return "Recursion can be used to find the nth Fibonacci number by breaking the problem down into smaller subproblems. A recursive function would call itself with the next two preceding Fibonacci numbers until the base case (1 or 0) is reached. The results from each recursive call are then combined to get the final nth Fibonacci number."
      elif problem == "Solve problems using recursion":
          return "Recursion is a powerful technique for solving problems. It involves defining a problem in terms of itself. A recursion problem is solved by breaking it down into smaller problems, until the problem is small enough to be solved directly. The result from a smaller problem can then be combined with the result from the larger problem, until the original problem is solved."
      elif problem == "":
          return "Recursion is a technique where a function calls itself in order to solve a problem. It involves breaking the problem down into smaller instances of the same problem, until a base case is reached where the problem can be solved directly. The results from these smaller problems are then combined to solve the original problem."
      else:
          return "Recursion is a technique where a function calls itself in order to solve a problem. It involves breaking the problem down into smaller instances of the same problem, until a base case is reached where the problem can be solved directly. The results from these smaller problems are then combined to solve the original problem."