[Data structure] Divide and conquer code template

Source: Qin Chao

Python

def divide_conquer(problem, param1, param2, ...): 
  # recursion terminator 
  if problem is None: 
	print_result 
	return 

  # prepare data 
  data = prepare_data(problem) 
  subproblems = split_problem(problem, data) 

  # conquer subproblems 
  subresult1 = self.divide_conquer(subproblems[0], p1, ...) 
  subresult2 = self.divide_conquer(subproblems[1], p1, ...) 
  subresult3 = self.divide_conquer(subproblems[2], p1, ...) 
  …

  # process and generate the final result 
  result = process_result(subresult1, subresult2, subresult3, …)
	
  # revert the current level states

C/C++

int divide_conquer(Problem *problem, int params) {
    
    
  // recursion terminator
  if (problem == nullptr) {
    
    
    process_result
    return return_result;
  } 

  // process current problem
  subproblems = split_problem(problem, data)
  subresult1 = divide_conquer(subproblem[0], p1)
  subresult2 = divide_conquer(subproblem[1], p1)
  subresult3 = divide_conquer(subproblem[2], p1)
  ...

  // merge
  result = process_result(subresult1, subresult2, subresult3)
  // revert the current level status
 
  return 0;
}

Javascript

const divide_conquer = (problem, params) => {
    
    

  // recursion terminator

  if (problem == null) {
    
    

    process_result

    return

  } 

  // process current problem

  subproblems = split_problem(problem, data)

  subresult1 = divide_conquer(subproblem[0], p1)

  subresult2 = divide_conquer(subproblem[1], p1)

  subresult3 = divide_conquer(subproblem[2], p1)

  ...

  // merge

  result = process_result(subresult1, subresult2, subresult3)

  // revert the current level status

}

Java

private static int divide_conquer(Problem problem, ) {
    
    
  
  if (problem == NULL) {
    
    
    int res = process_last_result();
    return res;     
  }
  subProblems = split_problem(problem)
  
  res0 = divide_conquer(subProblems[0])
  res1 = divide_conquer(subProblems[1])
  
  result = process_result(res0, res1);
  
  return result;
}